Chemistry Archives - Noon Academy

Chemistry

Option A NH3(g) Option B H2(g) Option C N2(g) Option D CH4(g) Solution: Correct Option A NH3 will show maximum deviation from ideal gas because of the dipole-dipole attraction.

$6.02\text{ }\times \text{ }{{10}^{20}}$ molecule of urea are present in 100mL of its solution. The concentration of solution is:-

Chemistry

Option A 0.1 M Option B 0.02 M Option C 0.01 M Option D 0.001 M Solution: Correct Option C The number of moles of urea to (volume in L) of the solution equals the concentration of the solution. The...

Chemistry

Option A 1, 2, 4-Trinitrobenzene Option B 1, 2-Dinitrobenzene Option C 1, 3- Dinitrobenzene Option D 1, 4- Dinitrobenzene Solution: Correct Option C Nitrobenzene on reaction with conc....

Chemistry

Option A BaCl2 Option B TeF2 Option ICl2- Option D SbCl3 Solution: Correct Option C Isostructural species are the species having the same number of bond pairs and lone pairs. There are 3 lone pairs...

Nylon is an example of:-

Chemistry

Option A Polythene Option B Polyester Option C Polysaccharide Option D Polyamide Solution: Correct Option D Nylon is formed by the condensation reaction of amines and carboxylic acid groups with...

The order of stability of the following tautomeric compounds is:

Chemistry

Option A II > III > I Option B I > II > III Option C III > II > I Option D II > I > III Solution: Correct Option C The order of tautomeric compound stability is...

In the reaction:

Chemistry

Solution: Correct Option D

Based on equation $E=-2.178\times {{10}^{-18}}\left( \frac{{{Z}^{2}}}{{{N}^{2}}} \right)$ certain conclusions are written. Which of them is not correct?

Chemistry

Option A For n = 1, the electron has more negative energy than it does for n = 6 which means that the electron is more loosely bound in the smallest allowed orbit. Option B The negative sign in the...

The number of Faradays (F) required to produce $20 g$ of calcium from molten $CaCl _{2}$ (Atomic mass of $\left.Ca =40 g mol ^{-1}\right)$ is
A 2
B 3
C 4
D 1

Chemistry

Correct Option D) As we know $$ \begin{aligned} & w = ZQ \\ & Q =\frac{ w }{ Z }=\frac{20}{40 / 2} F =1 F \end{aligned} $$ where $Z =\frac{ E }{ F }$

Which of the following is not correct about carbon monoxide?
A. The carboxyhemoglobin (haemoglobin bound to CO) is less stable than oxyhaemoglobin.
B. It is produced due to incomplete combustion.
C. It forms carboxyhaemoglobin.
D. It reduces oxygen carrying ability of blood

Chemistry

Correct Option A) Because CO is a stronger ligand than oxygen, carboxyhemoglobin is a more stable complex.

Which one of the following molecules contains no π bond?

Chemistry

Option A NO2 Option B CO2 Option C H2O Option D SO2 Solution: Correct Option C The central atom of oxygen has no d-orbitals for ????-bonding in the H2O molecule.

On electrolysis of dil. Sulphuric acid using platinum (Pt) electrode, the product obtained at anode will be: A. $\quad H _{2} S$ gas B. $SO _{2}$ gas C. Hydrogen gas D. Oxygen gas

Chemistry

Correct Option: D) Solution: The reactions are as follows: Dissociation of sulfuric acid, $H _{2} SO _{4} \rightarrow 2 H ^{+}( aq )+ SO _{4}^{-2}( aq )$ Disssociation of water, $H _{2} O...

Which of the following lanthanoid ions is diamagnetic? (At. No., Ce = 58, Sm = 62, Vb = 70)

Chemistry

Option A Yb 2+ Option B Ce 2+ Option C Sm2+ Option D Eu2+ Solution: Correct Option A Diamagnetic means no unpaired electrons Ce (58) = Ce2+ = [Xe] 4f2 5d0 6s2, unpaired e⎺ = 2 Sm (62)= Sm2+ =...

Find out the solubility of $Ni ( OH )_{2}$ in $0.1 M NaOH$ . Given that the ionic product of $Ni ( OH )_{2}$ is $2 \times 10^{-15}$
A $2 \times 10^{-8} M$
B $1 \times 10^{-13} M$
C $1 \times 10^{8} M$
D $2 \times 10^{-13} M$

Chemistry

Correct Option D) Solution: $Ni ( OH )_{2}( s ) \leftrightharpoons Ni ^{+2}( aq )+2 OH ^{-}( aq )$ Thus we write the ionic product as, Ionic product $=\left[ Ni ^{+2}\right]\left[ OH...

For the reaction, $2 Cl ( g ) \rightarrow Cl _{2}( g )$ , the correct option is: A. $0 \Delta_{ r } H <0$ and $\Delta_{ r } S >0$ B. $\quad \Delta_{ r } H <0$ and $\Delta_{ r } S <0$ C. $\quad \Delta_{ r } H >0$ and $\Delta_{ r } S >0$ D. $\quad \Delta_{ r } H >0$ and $\Delta_{ r } S <0$

Chemistry

Correct Option: B) $2 Cl ( g ) \rightarrow Cl _{2}( g )$ As bond formation is accompanied by the release of energy $\therefore \Delta H =$-ve. Also, the number of particles decreases so $\Delta S =-...

How many grams of concentrated nitric acid solution should be used to prepare 250 mL of 2.0 M HNO3?

Chemistry

Option A 54. 0 conc. HNO3 Option B 45.0 conc. HNO3 Option C 90.0 conc. HNO3 Option D 70.0 conc. HNO3 Solution: Correct Option B

Hydrolysis of sucrose is given by the following reaction. Sucrose $+ H _{2} O \rightleftharpoons$ Glucose $+$ Fructose If the equilibrium constant $\left( K _{ C }\right)$ is $2 \times 10^{13}$ at $300 K$ , the value of $\Delta_{ r } G ^{\ominus}$ at the same temperature will be :
A $\quad 8.314 J mol ^{-1} K ^{-1} \times 300 K \times \ln \left(2 \times 10^{13}\right)$
B $\quad 8.314 J mol ^{-1} K ^{-1} \times 300 K \times \ln \left(3 \times 10^{13}\right)$
C $\quad-8.314 J mol ^{-1} K ^{-1} \times 300 K \times \ln \left(4 \times 10^{13}\right)$
D $\quad-8.314 J mol ^{-1} K ^{-1} \times 300 K \times \ln \left(2 \times 10^{13}\right)$

Chemistry

Correct Option D) The equation for the relationship between Gibbs energy and equilibrium constant is: $\Delta G ^{0}=- RT \ln K _{ c }$ $=-8.314 \times 300 \times \ln \left(2 \times...

Identify a molecule which does not exist. A. $C _{2}$ B. $O _{2}$ C. $He _{2}$ D. $Li _{2}$

Chemistry

Correct Option: C) He atom electronic configuration – $1s_2$ The electronic configuration of the He 2 molecule is $\sigma 1 s ^{2} \sigma * 1 s ^{2}$ according to the linear combination of atomic...

Which of the following statements about the interstitial compounds is incorrect?

Chemistry

Option A They have higher melting points than the pure metal Option B They retain metallic conductive Option C They are chemically reactive Option D They are much harder than the pure metal...

The rate constant for a first order reaction $4.606 \times$ $10^{-3} 8^{-1}$ . The time required to reduce $2.0 g$ of the reactant to $0.2 g$ is: A. $500 s$ B. $\quad 1000 s$ C. $100 s$ D. $\quad 200 s$

Chemistry

Correct Option: A) We calculate the time by $t =\frac{2.303}{ k } \log \frac{ A }{ A _{0}}=\frac{2.303}{4.606 \times 10^{-3}} \log \frac{2}{0.2}=500 sec$

The number of protons. Neutrons and electrons Lu. respectively, are:
A. 71, 71 and 104
B. 175, 104 and 71
C. 71, 104 and 71
D. 104, 71 and 71

Chemistry

Correct Option: D) Solution: ${ }_{71}^{175} Lu$ $n_{ p }= n _{e}=71$ $n _{ p }+ n _{ n }=175$ $n _{ n }=175-71=104$