Solution: Option (i) and (iv) are the answers. Group 13 elements create electron-deficient compounds and are thus Lewis acids. Electron-rich hydrides have lone pairs of extra electrons. Compounds of...
Solution: Option (ii) and (iii) are the answers. Inorganic electron-specific hydrides are those hydrides in which the exact quantity of electrons required to form a typical covalent bond is present....
Solution: Option (i) and (ii) are the answers. Permanent hardness is caused by the presence of soluble magnesium and calcium salts in the form of chorides and sulphates in the water, which causes...
Solution: Option (iii) and (iv) are the answers. In ice, there is a great deal of hydrogen bonding. Because of the empty spaces found in tetrahedrons generated by hydrogen bonding, ice is...
Solution: Option (i) and (iii) are the answers. Heavy water is a moderator in nuclear reactors. It has a greater boiling point than regular water. It is thus more associated than plain water....
Solution: Option (i) and (ii) are the answers. It is used to produce hydrogen, carbon monoxide, and other products from hydrocarbons like natural gas. This is done in a reformer, which uses...
Solution: Option (iii) and (iv) are the answers. Because hydrogen has only one electron in its outermost shell, it can form diatomic molecules by covalent bonding. Its high ionisation enthalpy...
Solution: Option (i) is the answer. Chromium (Cr), the single element in group 6, is capable of forming hydride. Because of their poor affinity for hydrogen, the other elements do not combine to...
Solution: Option (i) is the answer. The elements in groups 7, 8, and 9 have a low affinity for hydrogen, as a result of which they have little potential to combine with hydrogen to create...
Solution: Option (iii) is the answer. Water softening is done with sodium hexametaphosphate (Calgon). Calgon interacts with calcium/magnesium salts in hard water to create inactive complex anions...
Solution: Option (i) is the answer. Ca++ ions in the form of Ca(HCO3)2 or CaCl2 or CaSO4 causing hardness in water, or more specifically, soluble calcium salts, is possible.
Solution: Option (iv) is the answer. The mixture of carbon monoxide and hydrogen is referred to as water gas. The term "synthesis gas" or "syngas" refers to the mixture of carbon monoxide and...
Solution: Option (ii) is the answer. The simplest peroxide (oxygen-oxygen single bond) is hydrogen peroxide. It is an oxidizing agent utilized in many synthetic processes. In the industrial...
Solution: Option (iv) is the answer. In the reaction of sodium peroxide with dilute sulphuric acid, we obtain the byproduct sodium sulphate and hydrogen peroxide as a result.
Answer: The presence of electronegative elements like oxygen, fluorine, and nitrogen causes particularly stable intermolecular hydrogen bonding (bonding with other molecules of the same or other...
Answer: A polar molecule is one that has a charge distribution that is slightly positive on one side and slightly negative on the other. It is possible to increase polarity by increasing the...
Answer: H2O2, also known as hydrogen peroxide, is a powerful oxidizing agent that can be used in both acidic and basic conditions. Because of the release of nascent oxygen, it has the effect of...
Answer: Hydrogen peroxide (H2O2) is an oxygen hydride with the chemical formula H2O2. It has the ability to serve as an oxidizing as well as a reducing agent in both acidic and basic mediums,...
Answer: Lewis structures are diagrams that represent the bonding between atoms in a molecule, as well as any lone pairs of electrons that may occur.
Answer: Heavy water is defined as water that contains a high concentration of heavy hydrogen (D2O). It is utilised as a moderator in nuclear reactors and exchange processes, and it is also employed...
Answer: It is easier to transport because it is a liquid and consumes less volume than other forms of transportation. Consequently, the most fundamental attribute of hydrogen that is advantageous...
Answer: A valence electron from the H atom is harder to remove than from the Na atom because of the higher nuclear attraction, and hence more energy would be required. As a result, the ionization...
Answer: Because hydrogen has just one electron in its outermost shell, it can either lose or gain an electron in order to achieve the noble gas configuration. Hydrogen has a high ionization...
Answer: In its electronic form, hydrogen shares features with alkalis and halogens. Like alkali metals (ns1), hydrogen (1s1) has only one electron in its valence shell. So if they lose one electron,...
Answer: The compound hydrogen peroxide, which functions as both an oxidising and reducing agent in both acidic and alkaline conditions, is referred to as hydrogen peroxide. After coming into touch...
Answer: The first element, hydrogen, interacts with dioxygen to make water. Water is amphoteric, meaning it is both acid and basic. Water's solid state is ice. Due to its decreased density, it...
Answer: In order to break the H-F bond, a large amount of energy must be expended in order to build a strong and stable hydrogen bond. As a result, the boiling point of HF is higher than that of...
Answer: The values associated with the attributes of D2O are higher than those associated with H2O. As a result, we can conclude that the intermolecular forces in D2O are stronger.
Answer: i) The diagram shows the gas phase and solid phase structure of H2O2. ii) When the oxygen atom on H2O2 is reduced to -1, it is considered to be in an intermediate state of oxidation. Meaning...
Answer: $H_2O_2$ has a molar mass of 34gm and is a gas. According to this reaction, 2 moles of peroxide are involved, resulting in a total mass of 68g. We already know that 1mole of any gas occupies...
Answer: When $D_2SO_4$ interacts with $BaO_2, D_2O_2$ is generated, which is then followed by the formation of barium sulphate ($BaSO_4$). In the presence of $D_2SO_4 + BaO_2 → D_2O_2 +...
Answer: Heavy water, which is composed primarily of deuterium oxide (D2O), is produced primarily by the electrolysis of regular water. 1. Ordinary water has a molecular mass of 18.015 while heavy...
Answer: Molecular hydrides are classed as electron-deficient, electron-rich, or precise. B2H6 is an oxyhydroxide. They lack an octet. Generally, group 13 elements like B, Al, etc. create them. This...
Answer: Water is demineralized by passing it through anion and cation exchange resin. It has many of SO3H and COOH groups. A cation exchanger removes cations like Na+ and Mg+ from the water. OH-,...
Answer: Water that has undergone auto protolysis has undergone self ionisation. It is a chemical property of water that is important to understand. In this case, two identical molecules react to...
b) 
Answer: (i) $PbS (s) + H_2O_2 (aq) → PbSO_4 + 4H_2O$ This is a redox reaction. PbS (oxidation state -2) is oxidized to PbSO4 (oxidation state +6) and H2O2 by hydrogen peroxide (oxidation state of O...
Answer: When water freezes, it expands, resulting in a volume of ice that is more than the volume of the water for the same quantity of water. We can state that ice has a lower density than water...
Answer: Heat conductivity and electrical conductivity of metal hydrides are quite high, while the conductivity and electrical conductivity of molecular hydrides are extremely low. Metallic hydrides...
Answer: It is necessary to apply the water shift gas process in the generation of synthesis gas (a mixture of hydrogen and carbon monoxide or carbon dioxide). CO is transformed to CO2 in this...
Solution: Option (iii) is the answer. It is also known as dioxide or peroxide. It has a mild odor and is colorless in solution. With a stabilizer, it is non-flammable and somewhat acidic. An...
? (i) 
(ii) 
(iii) 
(iv) 
Solution: Option (iii) is the answer. The oxidising characteristic of $H _2 O _2$ indicates that it oxidises other substances while simultaneously reducing itself. In such reactions, $O _2$ does not...
Solution: Option (ii) is the answer. The oxide that gives $H _{2} O _{2}$ on treatment with dilute $H _{2} SO _{4}$ is $BaO _{2} \cdot 8 H _{2} O$....
Solution: Option (ii) is the answer. (A) $H_2O_2 + 2HI → I_2 + 2H_2O$ Iodine undergoes oxidation, transitioning from the -1 oxidation state to the 0 oxidation state. As a result, H2O2 works as an...
Solution: Option (iii) is the answer. The concentration of tritium is approximately one atom per $10^18$ atoms of protium in the sample. Only tritium is radioactive and emits low-energy beta...
Solution: Option (iv) is the answer. The hydrides indicate an anion form of hydrogen atoms. ...
Solution: Option (ii) is the answer. As we advance down the group, the ionic nature rises. As ionisation enthalpy drops from top to bottom in a group, metal tends to lose electron. So ionic...
Solution: Option (iv) is the answer. Hydrogen has one electron in its s orbital and like alkali metals, it can lose one electron from its outer shell. So hydrogen is like alkalis. Onions reacting...
Solution: Option (ii) is the answer. Hydrogen, like halogens, prefers to gain an electron to achieve a stable noble gas structure. Hydrogen's electrical configuration is 1s. The electrical...
Option I is the correct response.
is under a tension of 
. The length of the stretched string is 
. If the transverse jerk is struck at one end of the string, how long does the disturbance take to reach the other end?Mass of the string is given as $M=2.50 kg$ Tension in the string is given as $T=200 N$ Length of the string is given as $\mid=20.0 m$ Mass per unit length will be, $\mu=\mathrm{M} / \mathrm{I}=5 /...
Solution: \[\begin{array}{*{35}{l}} ~P1\text{ }=\text{ }1\text{ }bar \\ P2\text{ }=\text{ }? \\ ~V1=\text{ }500\text{ }dm3 \\ V2=200\text{ }dm3 \\ \end{array}\] As temperature stays steady at...
Solution: \[\begin{array}{*{35}{l}} ~P1\text{ }=\text{ }1\text{ }bar \\ P2\text{ }=\text{ }? \\ ~V1=\text{ }500\text{ }dm3 \\ V2=200\text{ }dm3 \\ \end{array}\] As temperature stays steady at...
and length 
is stretched ( not beyond its elastic limit ) horizontally between two columns. If a 
mass is hung at the midpoint of the wire, find the depression at the midpoint.Solution: Let $Y Z$ be a mild steel wire with a cross sectional area of $A=0.60 \times 10^{-2} cm^{2}$ and a length of 2m. As indicated in the image, a mass of $m=100g=0.1kg$ is hanged from the...
What is the maximum tension that can be exerted by the riveted strip if the shearing stress on the rivet is not to exceed 
Pa? Assume that each rivet is to carry one-quarter of the load.Diameter of the metal strips is given as $6 \mathrm{~mm}=6 \times 10^{-3} \mathrm{~m}$ Radius will be then, $r=3 \times 10^{-3} \mathrm{~m}$ Shearing stress on the rivet is given as $6.9 \times...
having negligible mass is supported at its ends by two wires of steel (wire A) and aluminium (wire B) of equal lengths as shown in the figure. The cross-sectional areas of wires 
and 
are 
and 
, respectively. At what point along the rod should a mass 
be suspended in order to produce (a) equal stresses and (b) equal strains in both steel and aluminium wires.Solution: Cross-sectional area of wire A is given as $a_{1}=1.0 \mathrm{~mm}^{2}=1.0 \times 10^{-6} \mathrm{~m}^{2}$ Cross-sectional area of wire B is given as $a_{2}=2 m m^{2}=2 \times 10^{-6}...
The diameter of the flat faces at the narrow end of the anvil is given as, $d=0.50mm=0.5\times 10^{-3} m$ Radius will be, $r=d/2=0.25\times 10^{-3} m$ Compressional force is given as $F=50000N$...
?Volume of water is given as $V=1$ litre Water should be compressed by $0.10 \%$ is given The fractional change in volume will be, $\Delta \mathrm{V} N=(0.1 / 100) \times 1=10^{-3}$ Bulk modulus,...
atm, given that its density at the surface is 
?Let the depth be 'd' Pressure at the given depth is given as $p=60\times1.01\times10^{5}Pa$ Density of water at the surface is given as $\rho_{1}=1.03\times10^{3}$ $kg$ $m^{3}$ Let $\rho_{2}$ be the...
is supported symmetrically by three wires each 
long. Those at each end are of copper and the middle one is of iron. Determine the ratios of their diameters if each is to have the same tension.The extension of each wire will be the same because the stress on the wires is the same. Now that the wires are the same length, the tension on them will be the same. Now, we know: $Y=Stress /...
supports a chairlift at a ski area. If the maximum stress is not to exceed 
What is the maximum load the cable can support?Radius of the steel cable is given as $r=1.5 \mathrm{~cm}=0.015 \mathrm{~m}$ Cross-sectional area of the cable will be, $\pi r^{2}=3.14 \times(0.015)^{2}$ $=7.06 \times 10^{-4} \mathrm{~m}$ Maximum...
. The inner and outer radii of each column are 
and 
respectively. Assuming the load distribution to be uniform, calculate the compressional strain of each column.Mass of the big structure is given as $M=50,000 \mathrm{~kg}$ Total force exerted on the four columns will be equal to the total weight of the structure, that is, $50000 \times 9.8 \mathrm{~N}$ The...
long. One face of the cube is firmly fixed to a vertical wall. A mass of 
is then attached to the opposite face of the cube. The shear modulus of aluminium is 
. What is the vertical deflection of this face?Edge of the aluminium cube is given as $L=10 \mathrm{~cm}=10 / 100=0.1 \mathrm{~m}$ Area of each face wil be, $A=(0.1)^{2}=0.01 \mathrm{~m}^{2}$ Mass attached to the opposite face of the cube is...
, one made of steel and the other made of brass are loaded as shown in Fig. The unloaded length of steel wire is 
and that of brass wire is 
. Compute the elongations of the steel and the brass wires. [Young’s modulus of steel is 
![\left.10^{11} \mathrm{~Pa} .\left(1 \mathrm{~Pa}=1 \mathrm{~N} \mathrm{~m}^{2}\right)\right]](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-36c8cbb599d2f5fc96ae57f00cbbd2ee_l3.png "Rendered by QuickLaTeX.com")
Diameter of the two wires is given as $d=0.25 \mathrm{~m}$ Radius of the wires is given as $r=d / 2=0.125 \mathrm{~cm}$ Unloaded length of the steel wire is given as $l_{1}=1.5 \mathrm{~m}$ Unloaded...
and are shown in the figure below.(a) Which of the materials has the greater Young's modulus? (b) Which of the two is the stronger material? Solution: (a) We can observe from the graphs that for a given strain, $A$ has a higher...
and cross-sectional area 
stretches by the same amount as a copper wire of length 
and cross-sectional area of 
under a given load. What is the ratio of Young’s modulus of steel to that of copper?Length of the steel wire is given as $l_{1}=4.7 \mathrm{~m}$ Cross-sectional area of the steel wire is given as $a_{1}=3.0 \times 10^{-5} \mathrm{~m}^{2}$ Length of the copper wire is given as...
with a mass of 
. A child whose mass is 20 kg runs on the trolley with a speed of 
from one end to other which is 
. The speed is relative to the trolley in the direction opposite to its motion. Find the final speed of the trolley and the distance the trolley moved from the time the child began to run.Mass is given as $m=200 \mathrm{Kg}$ Speed is given as $v=36 \mathrm{~km} / \mathrm{h}=10 \mathrm{~m} / \mathrm{s}$ Mass of boy is given as $=20 \mathrm{Kg}$ Initial momentum will be, $(M+m) v$...
falls from the ceiling of an elevator moving down with a uniform speed of 
. It hits the floor of the elevator (length of elevator 
) and does not rebound. What is the heat produced by the impact? Would your answer be different if the elevator were stationary?Mass of the bolt is given as $m=0.3 \mathrm{~kg}$ Potential energy of the bolt is given as $m g h=0.3 \times 9.8 \times 3=8.82\rfloor$ The bolt does not return to its original position. As a result,...
block situated on a rough incline is connected to a spring of spring constant 100 
as shown in Fig. The block is released from rest with the spring in the unstretched position. The block moves down the incline before coming to rest. Find the coefficient of friction between the block and the incline. Assume that the spring has a negligible mass and the pulley is frictionless.Solution: Spring constant is given as $\mathrm{k}=100 \mathrm{~N} \mathrm{~m}^{m}$ Displacement in the block is given as $\mathrm{x}=10 \mathrm{~cm}=0.1 \mathrm{~m}$ At equilibrium: Normal reaction...
and horizontal speed 
strikes a block of wood of mass 
and instantly comes to rest with respect to the block. The block is suspended from the ceiling by means of thin wires. Calculate the height to which the block rises. Also, estimate the amount of heat produced in the block.Mass of the bullet is given as $m_{1}=0.012 \mathrm{~kg}$ Initial speed of the bullet is given as $u_{1}=70 \mathrm{~m} / \mathrm{s}$ Mass of the wooden block is given as $m_{2}=0.4 \mathrm{~kg}$...
each time. Assume that the potential energy lost each time she lowers the mass is dissipated. (a) How much work does she do against the gravitational force? (b) Fat supplies 
of energy per kilogram which is converted to mechanical energy with a 
efficiency rate. How much fat will the dieter use up?Mass is given as $\mathrm{m}=10 \mathrm{~kg}$ Height to which the mass is lifted is given as $h=0.5 \mathrm{~m}$ Number of times is hiven as $n=1000$ (a) Work done against gravitational force can be...
travels in a straight line with velocity 
where 
. What is the work done by the net force during its displacement from 
to 
m?Let the mass of the body be $m$ $m=0.5 \mathrm{~kg}$ Velocity of the body is represented by $v=a x^{3 / 2}$ where, $a=5 \mathrm{~m}^{-1 / 2} \mathrm{~s}^{-1}$. Initial velocity at $x=0$ will be...
, what is the speed with which the bob arrives at the lowermost point, given that it dissipated 
of its initial energy against air resistance?Length of the pendulum is given as $\mid=1.5 \mathrm{~m}$ Potential of the bob at the horizontal position is given as $=m g h=m g \mid$ When the bob goes from the horizontal position to the lowest...
. If the collision is elastic, which of the following figure is a possible result after collision?Solution: The mass of the ball bearing is given as $\mathrm{m}$ Before the collision, Total Kinetic Energy of the system will be $=1 / 2 m v^{2}+0=1 / 2 m v^{2}$ After the collision, Total Kinetic...
and angle 
with the normal, and rebounds with the same speed. Is momentum conserved in the collision? Is the collision elastic or inelastic?For an elastic or inelastic collision, momentum is always preserved. The molecule approaches and rebounds with the same speed of $200 \mathrm{~m} / \mathrm{s}$. $u=v=200 \mathrm{~m}...
, and the second with 
. Which is faster, the electron or the proton? Obtain the ratio of their speeds. (electron mass 
, proton mass 
)Electron mass is given as $m_{e}=9.11 \times 10^{-31} \mathrm{~kg}$ Proton mass is given as $m_{p}=1.67 \times 10^{-27} \mathrm{~kg}$ Electron's kinetic energy can be calculated as...
Power is given by, $P=F V$ $=\operatorname{mav}=\operatorname{mv} \frac{d v}{d t}$ vdv $=\frac{k}{m} \mathrm{dt}$ On integration, we get, 10 $\frac{v^{2}}{2}=\frac{k}{m} d t$...
(a) In an inelastic collision, there will be a loss of kinetic energy. After a collision, the K.E is always lower than the K.E before the impact. In an inelastic collision, the system's total linear...
(a) False. The work done by the conservative force on the moving body in a closed loop is zero. (b) True
(a) External force Internal forces, regardless of their direction, cannot cause a change in momentum. As a result, the change in total momentum is proportional to the system's external force. (b)...
(a) Decreases When a body is displaced in the direction of the force, the conservative force does positive work on it, causing the body to migrate to the center of force. As a result, the distance...
carrying a mass of on his hands. In Fig., he walks the same distance pulling the rope behind him. The rope goes over a pulley, and a mass of hangs at its other end. In which case is the work done greater?Solution: (a) As the satellite approaches the Earth, its potential energy drops, and since the system's total energy should remain constant, the kinetic energy increases. As a result, the...
, where 
is the force constant of the oscillator. For 
, the graph of 
versus 
is shown in Figure. Show that a particle of total energy 
moving under this potential must ‘turn back’ when it reaches 
.Solution: Energy of the particle will be, $\mathrm{E}=1 \mathrm{~J}$ $\mathrm{K}=0.5 \mathrm{~N} \mathrm{~m}^{-1}$ $\mathrm{K} . \mathrm{E}=\frac{1}{2} \mathrm{mv}^{2}$ Based on law of conservation...
(a) (b) The total energy is given by the relation, $E=K . E .+P . E$. So, $K_{. E}=E-P . E .$ There can never be a negative amount of kinetic energy. In the region where K.E. becomes negative, the...
initially at rest moves under the action of an applied horizontal force of 
on a table with the coefficient of kinetic friction 
Compute the
,.Mass of the body is given as $2 \mathrm{~kg}$ Horizontal force applied is given as $7 \mathrm{~N}$ Coefficient of kinetic friction is given as $0.1$ Acceleration produced by the applied force can be...
Work completed is negative. It is noticed that the bob's orientation and the air resistance acting on it are in different directions.
(a) The direction of motion of the object is opposite the direction of the frictional force, as can be seen. As a result, the work completed is negative. (b) The frictional force acting on an object...
(i) Both A and R are true and R is the correct explanation of A. (ii) Both A and R are true but R is not the explanation of A. (iii) A is true and R is false. (iv) Both A and R are false. ...
(i) Both A and R are true and R is the correct explanation of A. (ii) Both A and R are true and R is not the correct explanation of A. (iii) A is true and R is false. (iv) Both A and R are false....
(i) Both A and R are true and R is the correct explanation of A. (ii) Both A and R are true but R is not the correct explanation of A. (iii) A is true but R is false. (iv) Both A and R are false....
Column 1 Column 2 (i) Cr (a) [Ar]3d84s0 (ii) Fe2+ (b) [Ar]3d104s1 (iii) Ni2+ (c) [Ar]3d64s0 (iv) Cu (d) [Ar] 3d54s1 (e) [Ar]3d64s2 Column 1 Column 2 (i) Cr (d) [Ar]...
Column 1 Column 2 (i) Photon (a)Value is 4 for N shell (ii) Electron (b)Probability density (iii) ψ2 (c)Always a positive value (iv) The principal quantum number n (d)Exhibits both momentum...
Column 1 Column 2 (i) X-rays (a) ν = 100-0 104 Hz (ii) UV (b) ν = 1010Hz (iii) Long radio waves (c) ν = 1016 Hz (iv) Microwave (d) ν = 1018Hz Column 1 Column 2 (i) X-rays (d) ν = 1018Hz (ii) UV...
Rule Principle (i) Hund’s Rule (a) No two electrons in an atom can have the same set of four quantum numbers. (ii) Aufbau Principle (b) Half-filled and filled orbitals have extra stability....
Column 1 Column 2 (i) Principal quantum number (a) orientation of the orbital (ii) Azimuthal quantum number (b) energy and size of orbital (iii) Magnetic quantum number (c) spin of an electron (iv)...
Atom / Ion Electronic configuration (i) Cu (a) 1s2 2s2 2p6 3s2 3p6 3d10 (ii) Cu2+ (b) 1s2 2s2 2p6 3s2 3p6 (iii) Zn2+ (c) 1s2 2s2 2p6 3s2 3p6 3d10 4s1 (iv) Cr3+ (d) 1s2 2s2 2p6 3s2 3p63d9 (e) 1s2...
Hydrogen atom has only one electron, so the mutual repulsion between the electrons is non-existent. However, in multielectron atoms the interaction between electrons is important. This is because,...
The uncertainty principle is applicable only for microscopic particles and can be concluded from the uncertainty measurement. Example: Take a particle of mass = 1 milligram ∆x. ∆ν = 60626*10-34/...
According to Heisenberg’s uncertainty principle: ∆x. ∆p ≥ h/4π Mass of the ball = 4 g Speed is = 90 m /s Uncertainity of speed, ∆v = 4/100 × 90 ∆v = 3.6 m/s ∆x = h/4πm∆v ∆x = 6.26 × 10-34 / 4 × 3.14...
Orbit represents a clear circular path for electrons to surround the nucleus. Represents the two-dimensional movement of electrons around the nucleus, the orbital is not that well defined because it...
The relationship between the wavelength and the frequency: λ = c/ν c - Velocity of light v - Frequency of the radiation. λ = 3 x 108 ms-1 / 4.620 x 1014 Hz Hence, λ = 0.6494...
Distance between the two identical successive points in a wave is called the wavelength. Given, In the hypothetical wave, Wavelength, λ = 4 × 2.16 pm Hence, Wavelength, λ = 8.64 pm.
The electron which is a lighter particle will have the higher velocity and will also produce matter waves having the same wavelength. This is because, if the mass is less, then the velocity increases.
The bright line spectrum shows that the atomic energy levels are measured. These lines are found to be the result of electronic transitions between energy and the atomic spectrum would have shown...
Calculation: Given, Mass, m = 100g / 0.1kg Velocity = 100km/h Velocity =100×1000 / 60×60 Velocity = 1000/36m/s λ =h/mν λ = 2.387 × 10-34 m
Calculation: According to Bohr’s model for the hydrogen atom; ν = RH(1/n12-1/ n22)cm-1 Given, n1 = 2 n2 = 4 H (Rydberg’s constant) = 109677 Wave number = 109677 ( ¼-1/16) Hence, Wave number =...
Great stability is established to the orbitals which are half or completely filled. In the given electronic configuration 3d104s1 of Copper (Cu), the stability is assured (d orbitals - filled, s...
λ(A) = 300 nm λ(B) = 300 μm λ(c) = 3 nm λ (D) 30 A° Arrange these radiations in the increasing order of their energies. Given, λ(A) = 300 nm λ(A) = 300 x 10-9 m λ(A) = 3 x 10 -7 m λ(B)...
Calculation: Atomic mass number = number of protons + number of neutrons Number of protons = atomic mass number – number of neutrons. Hence, atomic number of an atom = 13 – 7 = 6.
Neutron shows no deflection from the path passing through the electric field. This is due to the neutrality of neutron particles. Therefore, it has no charge and is not affected by any electrical...
Based upon the above information, arrange the following orbitals in the increasing order of energy (a) 1s, 2s, 3s, 2p (b) 4s, 3s, 3p, 4d (c) 5p, 4d, 5d, 4f, 6s (d) 5f, 6d, 7s, 7p Based upon the...
The region where the probability of finding the electrons is zero, it is considered as the nodes and is it present among the orbitals. Example: In the np orbitals, Nodes = n – l – 1 Nodes = 3 –1 – 1...
The electron energy in a multielectron atom, in contrast to the hydrogen atom, depends not only on its quantum number, but also on its azimuthal quantum number. The same electron shells and the same...
1 Ni atom = 28 electrons and its electronic configuration is 4s2 3d8 It turns to Ni2+ by losing 2 electrons and its electronic configuration becomes 4s0 3d8 According to the Aufbau principle, Ni...
Distribution of electrons in oxygen atom: 1s22s22p4
Arrangement of the subshells: d<p<s The s-orbitals shield the electrons a lot more when compared to the p-orbitals from the nucleus.
(i) The angular quantum number determines the three-dimensional shape of the orbital. (ii) The principal quantum number determines the orientation and energy of the orbital. (iii) The magnetic...
(i) Na+, Mg2+ (ii) Al3+, O– (iii) Na+, O2- (iv) N3-, Cl– Correct Answers: (i) Na+, Mg2+ (iii) Na+, O2- Explanation: Isoelectronic species are the atoms / ions that has the same number...
(i) 1 1 +2 (ii) 2 1 +1 (iii) 3 2 –2 (iv) 3 4 –2 Correct Answers: (ii) 2 1 +1 (iii) 3 2 –2 Explanation: The correct sets of quantum numbers are, n = 2, l = 1, m = +1 n = 3, l = 2, m =...
(i) (a) n = 3, l = 2, ml = –2, ms= − ½ (b) n = 3, l = 2, ml = –1, ms= − 1/2 (ii) (a) n = 3, l = 1, ml = 1, ms = + ½ (b) n = 3, l = 2, ml = 1, ms = +1/2 (iii) (a) n = 4, l = 1, ml = 1, ms = +...
(i) 6X12, 6Y13 (ii) 17X35, 6Y37 (iii) 6X14, 7Y14 (iv) 4X8, 5Y8 Correct Answers: (iii) 6X14, 7Y14 (iv) 4X8, 5Y8 Explanation: Isotopes are the atoms having same atomic number but...
(i) Electron (ii) An alpha particle (He2+) (iii) Neutron (iv) Proton Correct Answer: (ii) An alpha particle (He2+) Explanation: According to de Broglie's equation, the alpha particles...
(i) Zeff for an electron in a 2s orbital is the same as Zeff for an electron in a 2p orbital. (ii) An electron in the 2s orbital has the same energy as an electron in the 2p orbital. (iii) Zeff for...
(i) Cr3+, Fe3+ (ii) Fe3+, Mn2+ (iii) Fe3+, Co3+ (iv) Sc3+, Cr3+ Correct Answer: (ii) Fe3+, Mn2+ Explanation: Fe - Z=26 : 3d64s2 Fe3+- 3d5 Mn - Z=25 : 3d54s2 Mn2+ : 3d5 Hence,...
(i) l (ii) n and l (iii) n and m (iv) m and s Correct Answer: (i) l Explanation: Orbital angular momentum depends on the value of l which is referred to as the azimuthal quantum number.
(i) 2 (ii) 4 (iii) 9 (iv) 3 Correct Answer: (iii) 9 Explanation: The total number of orbitals in nth shell = n2 Hence, the total number of orbitals associated with the third shell will...
Correct Answer: (ii) Heisenberg’s uncertainty principle. Explanation: The Heisenberg's uncertainty principle states that it is impossible to know the exact position and speed of an object...
(i) 4 (ii) 3 (iii) 2 (iv) 1 Correct Answer: (iii) 2 Explanation: The Number of angular nodes = l (azimuthal quantum number) Hence, the number of angular nodes for 4d orbital is...
(i) 3 (ii) 4 (iii) 2 (iv) 1 Correct Answer: (iv) 1 Explanation: Number of radial nodes for 3p orbital = 3−1−1 Number of radial nodes for 3p orbital = 3−2 Number of radial nodes for 3p...
(i) they have the same atomic number but a different mass number. (ii) they have the same number of electrons but a different number of neutrons. (iii) they have the same number of neutrons but a...
(i) Overall neutrality of atom. (ii) Spectra of a hydrogen atom. (iii) Position of electrons, protons and neutrons in an atom. (iv) Stability of atom. Correct Answer: (i) Overall...
(i) It is a negatively charged particle. (ii) The mass of an electron is equal to the mass of a neutron. (iii) It is a basic constituent of all atoms. (iv) It is a constituent of cathode rays....
(i) They start from the cathode and move towards the anode. (ii) They travel in a straight line in the absence of an external electrical or magnetic field. (iii) Characteristics of cathode rays do...
The density of dots in a region represents the probability density of finding electrons in the region. Based on the above diagram which of the following statements is incorrect? (i) 1s and 2s...
(i) 1s2 2s2 2p6 3s2 3p6 3d8 4s2 (ii) 1s2 2s2 2p6 3s2 3p6 3d9 4s2 (iii) 1s2 2s2 2p6 3s2 3p6 3d10 4s1 (iv) 1s2 2s2 2p6 3s2 3p6 3d5 4s1 Correct Answer: (ii) 1s2 2s2 2p6 3s2 3p6 3d9 4s2...
(i) Most of the space in the atom is empty. (ii) The radius of the atom is about 10–10 m while that of a nucleus is 10–15 m. (iii) Electrons move in a circular path of fixed energy called orbits....
AB ab2 A,B A2B3 Mass of A (in g) 2 2 4 415 Mass of B (in g) 5 10 5 According to the law of multiple proportions, Masses of B combines with a constant mass of A are 10g, 20g, 5g, 15g Simple...
When two elements combine to form two or more chemical compounds, then the mass of one of the compounds in a fixed mass of the other holds a simple measure of each other is the law of equality....
CaCO3 (s) + 2HCl (aq) → CaCl2(aq) + CO2(g) + H2O(l) What mass of CaCl2 will be formed when 250 mL of 0.76 M HCl reacts with 1000 g of CaCO3? Name the limiting reagent. Calculate the number of moles...
(i) Calculation: Moles of oxygen = 1.6/32 Moles of oxygen = 0.05mol 1 mol of oxygen= 22.4L (at STP) Volume of Oxygen (V1) = 22.4 × 0.05 Volume of Oxygen (V1) = 1.12L V2 =? P1 = 1atm P2 = ½ P2 =...
Correct Answer: (iii) A is false but R is true Explanation: Combustion of 16 g of methane gives 36 g of water.
Correct Answer: (iii) A is true but R is false Explanation: Zero at the end of a number without the decimal point is not significantly based on the rate of accuracy.
Correct Answer: (ii) Both A and R are true but R is not the correct explanation of A Explanation: The carbon 12 isotope defines the mass of atoms and molecules.
Correct Answer: (i) Both A and R are true and R is the correct explanation of A Explanation: The empirical formula represents the simplest whole-number the ratio of various atoms present in a...
Physical quantity Unit (i) Molarity (a) g mL–1 (ii) Mole fraction (b) mol (iii) Mole (c) Pascal (iv) Molality (d) Unitless (v) Pressure (e) mol L–1 (vi) Luminous intensity (e) mol L–1 (vii) Density...
(i) 88 g of CO2 (a) 0.25 mol (ii) 6.022 ×1023 molecules of H2O (b) 2 mol (iii) 5.6 litres of O2 at STP (c) 1 mol (iv) 96 g of O2 (d) 6.022 × 1023 molecules (v) 1 mol of any gas (e) 3 mol ...
(i) The reactant B is the the limiting reagent. (ii) Calculation: Let us consider that the reactant B got completely consumed as it is the limiting reagent. 4 mol of B gives 3 mol of C 6 mol of B...
Calculation: Mole fraction of H2O = Number of moles of H2O / Total number of moles (H2O +NaOH) Number of moles of H2O = 36/18 Number of moles of H2O =2 moles Number of moles of NaOH = 4/40 Number of...
The Mass do not change when the temperature changes and so the molality of a solution do not change as well. Molality of a substance is defined as the number of mass of solute per mass of the...
Calculation: 3 molal solution of NaOH = 3 moles of NaOH dissolved in water 3 mole of NaOH = 120g Density of solution = 1.110gmL-1 Volume = mass/density Volume = 1120g/1.110gmL-1 Volume =1.009L...
Zn + 2HCl → ZnCl2 + H2 Calculate the volume of hydrogen gas liberated at STP when 32.65 g of zinc reacts with HCl. 1 mol of a gas occupies 22.7 L volume at STP; atomic mass of Zn = 65.3 u. ...
Isotope % Natural abundance Molar mass 1H 99.985 1 2H 0.015 2 Calculation: Average atomic mass of Hydrogen \[=099.985\times 1+\frac{0.015\times 2}{100}\] ...
(a) If two elements can combine to form more than one compound, the masses of one element that combine with a fixed mass of the other element, are in whole-number ratio and this statement is true....
2N2(g) + O2(g) → 2N2O(g) Which law is being obeyed in this experiment? Write the statement of the law? Answer: The Gay-Lussac’s law is used in the given reaction. The Gay-Lussac’s law states...
Calculation: Molecular mass of Ca3(PO4) = (3 X 40) + (2 X 31) + (8 X 16) Molecular mass of Ca3(PO4) = 310 Mass percentage of Ca = \[\frac{3\times 40}{310\times 100}\] Mass percentage of Ca = 38.71%...
Molarity Molality Number of moles per volume of the solution in litres Number of mass of solute per mass of the solvent in liters Unit - M Unit - m
Mole is the amount of substance containing more entities because there are atoms in 12 g of carbon. SI unit symbol – mol
Number Significant figures 2.5 2 1.25 3 3.5 2 2.01 3 In the given calculation, involving both the multiplication and division, the significant figures present is 2. Hence, the result cannot have...
1 mole of carbon atom = 12g Therefore, Mass of one atom of C-12 in grams= 1.99 × 1023 grams.
Correct Answers: (i) Law of conservation of mass; (iv) Avogadro's law Explanation: According to the Dalton's atomic theory, The Chemical compounds are formed when atoms of various elements join in a...
(i) Molality (ii) Molarity (iii) Mole fraction (iv) Mass per cent Answer: Correct Answers: (iii) Mole fraction; (iv) Mass per cent Explanation: Unit of Molality - Molal or moles per kg Unit...
(i) 16 g of CO (ii) 28 g of N2 (iii) 14 g of N2 (iv) 1.0 g of H2 Answer: Correct Answers: (iii) 14 g of N2; (iv) 1.0 g of H2 Explanation: The no. of molecules in N2 is 0.5 × 6.023 × 1023 The...
(i) 20 g of NaOH in 200 mL of solution (ii) 0.5 mol of KCl in 200 mL of solution (iii) 40 g of NaOH in 100 mL of solution (iv) 20 g of KOH in 200 mL of solution Answer: Correct Answers: (i)...
(i) 16 g of O2(g) and 4 g of H2(g) (ii) 16 g of O2 and 44 g of CO2 (iii) 28 g of N2 and 32 g of O2 (iv) 12 g of C(s) and 23 g of Na(s) Answer: Correct Answers: (iii) 28 g of N2 and 32 g of...
H2SO4 + 2NaOH → Na2SO4+ 2H2O When 1L of 0.1M sulphuric acid solution is allowed to react with 1L of 0.1M sodium hydroxide solution, the amount of sodium sulphate formed and its molarity in the...
(i) 6.022 × 1023 molecules of oxygen (ii) 6.022 × 1023 atoms of oxygen (iii) 16 g of oxygen (iv) 32 g of oxygen Answer: Correct Answers: (i) 6.022 × 1023 molecules of oxygen; (iv) 32 g of...
(i) Sample of carbon dioxide taken from any source will always have carbon and oxygen in the ratio 1:2. (ii) Carbon forms two oxides namely CO2 and CO, where masses of oxygen which combine with a...
(i) 2Mg(s) + O2(g) →2MgO(s) (ii) C3H8(g) + O2(g) → CO2(g) + H2O(g) (iii) P4(s) + 5O2(g) → P4O10(s) (iv) CH4(g) + 2O2(g) → CO2(g) + 2H2O (g) Answer: Correct Answer: (ii) C3H8(g) + O2(g) →...
Effective resistance = 1/R + 1/R = 2/R Current, I = V/(R/2) = 0.6A V/R = 0.3A switch is closed, Effective Resistance = Re 1/Re = 1/R + 1/R + 1/R = 3/R Re = R/3 Therefore, final current, I = V/(R/3)...
answer: Total current = I = I1 + I2 + I3 from ohms law I = V/R, I1 = V/R1 I2 = V/R2 I3 = V/R3 V/R = V/R1 + V/R2 + V/R3 1/R = 1/R1 + 1/R2 + 1/R3
Correct Answer: (i) The total mass of iron and oxygen in reactants = total mass of iron and oxygen in product therefore it follows the law of conservation of mass. Explanation: From the reaction,...
Correct Answer: (iii) A compound retains the physical properties of its constituent elements Explanation: Molecule of a compound is made up of atoms of various elements which cannot be separated...
Answer: i) Total resistance = R Given, R1 = 5 ohms R2 = 3+2 = 5 ohms 1/R = 1/5 + 1/5 R = 2.5 ohms ii) Current flowing through the circuit, I = V/R = 1.6 amps
Correct Answer: (i) 4.7g Explanation: Given, Density of solution = 3.12 g mL-1 Volume of solution = 1.5 mL Formula for Mass = Volume × Density Hence, Mass = 4.7 g
Correct Answer: (iii) C6H12O6 Explanation: Given, Molar mass of Carbon=12 Molar mass of Hydrogen=1 Molar mass of Oxygen=16 So, The molecular weight of compound is 6 and so the molecular formula of...
Correct Answer: (ii) 27.27% Explanation: Carbon dioxide is a gas with a density of about 53% higher than that of dry air. Carbon dioxide molecules consist of a double carbon atom combined with two...
Correct Answer: (iv) 1 m Explanation: According to molality of a substance which is the number of mass of solute per mass of the solvent in liters, the molality of the solution containing 18.25 g of...
Correct Answer: (iii) 0.005 M Explanation: According to the molarity of a substance which is defined as the number of moles per volume of the solution in litres, the molarity of the glucose in blood...
Correct Answer: (iv) 12g He Explanation: The number of atoms present in 4g of Helium – 1 NA The number of atoms present in 46g of Sodium - 2 NA The number of atoms present in 0.04g of Calcium – 0.01...
Correct Answer: (ii) 1.66 M Explanation: According to the Using M1V1= M2V2 formula, the value of M2 is 1.66 M.
Answer: The above circuit shows resistances R1 and R2 connected in series with a battery of V volts Total current = I = I1 + I2 apply ohms law, I=V/R I1 = V/R1 I2 = V/R2 V/R = V/R1 + V/R2 1/R = 1/R1...
c) B can be used in the making of the heating elements of an electric iron because the resistivity of B is the highest . d) C and E are the two substances that should be used for making electric...
Answer: a) E is the best conductor of electricity because it has the least resistivity . b) C is a better conductor between A and C because the resistivity of C is lesser than that of A .
Answer: Effective resistance = R 1/R = 1/R1 + 1/R2 + 1/R3 1/R=1/30 + 1/10 +1/5 R=3 ohm
Answer : c) Insulator is B = 1.0×1010 Ωm . d) Semiconductor is D = 2.3×103 Ωm .
Answer: A parallel circuit is a circuit in which the electricity travels over numerous separate pathways. i) Current through R1=6/5 = 1.2A Current through R2 =6/10= 0.6A Current through R3 =6/30=...
Answer: a) Good conductor is C = 10.0×10-8 Ωm . b) Resistor is A = 110×10-8 Ωm .
Answer: d) one-fourth is the correct answer. We know p=v²/R where R is constant p turns 1/4 times when V is halved The electric power is one-fourth of the actual value when the potential difference...
Show 
Where 
is the momentum of the 
particle (of mass 
and 
Note 
is the velocity of the 
particle with respect to the centre of mass.Also, verify using the definition of the centre of mass that 
Where 
is the total kinetic energy of the system of particles, 
is the total kinetic energy of the system when the particle velocities are taken relative to the center of mass and 
is the kinetic energy of the translation of the system as a whole.i)Here $\vec{r}_{i}=\vec{r}_{i}+\vec{R}+R \ldots$ also, $\vec{V}_{i}=\vec{V}_{i}+\vec{V} \ldots \ldots .$ Where $\vec{r}_{i}^{\overrightarrow{3}}$ and $\vec{v}_{i}^{\overrightarrow{3}}$ denote the...
Answer : c) For making of the solar cells, P = 2.3×103 Ωm can be used because this materials is a semiconductor .
Answer: c) 293 is the correct answer. When all 293 bulbs are linked in parallel and have 75W and 220V, a total of 293 bulbs can be used.
Answer: The resistances R1,R2 and R3 are linked in series with a V volt battery in the circuit above. Let V1 be the potential difference between R1 and V2 be the potential difference between R2....
Answer: a) For making of the electric wires, Q = 2.63×10-8 Ωm can be used because this material has a very low resistivity b) For making of the handle for soldering iron, R = 1.0×1015 Ωm can be used...
Answer: d) 3 J/s is the correct answer. Electrical energy transfered per second , E=VIt=6 x 0.5 x 1 When a light with a voltage of 6V and a current of 0.5A is utilised, 3 J/s of electrical energy is...
Answer: d) 15A is the correct answer. Current drawn by the kettle, I=P/V = 3000/230 So the cable should be able to carry more current than this and hence the answer is 15 A. An electric kettle with...
Answer: d) 6000J is the correct answer. According to the question, Power= 100 W Time, t = 1 minute = 60 seconds P=W/t W=6000J Energy is the ability to do work. Hence, In one minute, 6000J of energy...
Answer: given V=6V, Current through 5 ohm resistor =V/R= 2A i) V = IR R = 3 ohm ii) V = 10 + 6 = 16V
Answer: We know that, R = ρl/A Given that, l’ = 2l A’ = A/2 And ρ’ = ρ (as the material of the wire is the same) Therefore, R’ = ρ’l’/A’ = ρ2l/(A/2) = 4ρl/A = 4R Therefore, R’ = 4×20 =...
Answer: c) Kilowatt-hour is the right answer. The commercial unit of energy is the kilowatt hour.
Answer: a) Joule is the correct answer. The joule is the SI unit of energy.
Answer: The correct option is b) 2 times. Reason: As, R = ρl/A so R' = ρl/(A/2) = 2ρl/A ⇒R' = 2R So , new resistance becomes 2 times the original resistance .