(a) Na and K (b) K and C (c) Na and S (d) K and P Solution: Option (a) is the answer. Phenolphthalein is a synthetic indicator that remains colourless in acidic and neutral environments but turns...
Solution: (c) Sodium exists in solid form. It is a conductor of electricity and a source of basic oxides. As a result, sodium is classified as a metal. (d) Sulphur is a hard, brittle substance. It...
Solution: (a) Differences in physical properties between metals and non-metals 1. Metals are malleable, whereas nonmetallic materials are not. 2. Non-metals are non-ductile, whereas metals are...
(d) Name one metal that displaces copper from copper sulphate solution and one which does not. (e) Name one metal that displaces silver from silver nitrate solution and one which does not....
Solution: (a) A reactivity series is a vertical column of items arranged in decreasing order of their reactivities. Increasing order of reactivity : Iron< Zinc< Magnesium< Sodium (b)...
(e) Acidic or neutral oxides are formed when non-metals react with oxygen. Carbon dioxide is produced when carbon is burned in the air. C(s) + O2(g) → CO2(g) The resulting product is acidic....
(c) Iodine has a lustrous sheen to it. Iodine is a chemical element with atomic number 53 and the symbol I. (d) Carbon allotrope diamonds are extremely hard. Carbon is a chemical element with the...
d) Which fossil fuels were formed by the buried remains of small plants and animals? e) Which fossil fuel was formed by the buried remains of large land plants? Answer – c) The sun is regarded...
b) Describe how fossil fuels were formed. Answer – a) Fossil fuels are natural fuels that are created deep beneath the earth's surface from prehistoric species' remains. Fossil fuels include coal,...
Answer: LPG is an odourless material that can nonetheless be detected by its odour due to the addition of mercaptan to the LPG. The actions to take in the event of an LPG leak in the kitchen are as...
Answer: LPG is a better fuel than coal because when coal is burned, dangerous gases are released, however when LPG is burned, no harmful gases are generated..
Answer: Because of its calorific value and lack of hazardous gas production, LPG is considered a good fuel. LPG also has a high calorific value.
Answer: LPG is utilised as a source of energy for heating food since it has a high calorific value and produces smokeless flames.
Answer: Increasing the efficiency of the combustion process and developing strategies to decrease the discharge of toxic gases and ashes into nature are two steps that can be taken to control...
Answer: Increasing the efficiency of the combustion process and, developing strategies to decrease the discharge of toxic gases and ashes into nature are two steps that can be taken to control...
Answer: When fossil fuels are burned, acidic gases such as sulphur dioxide and nitrogen dioxide are released. Acid rain is caused by these chemicals, which harm trees, buildings, and plants while...
Answer: The following are some of the disadvantages of burning fossil fuels: a) Acidic gases are produced when fossil fuels are burned. b) The amount of smoke produced is higher, as is the amount of...
Answer: Heat is generated in thermal power plants by burning coal, which is then used to boil water and create steam. When high-temperature, high-pressure steam is introduced to turbines, it causes...
Answer: Traditional sources of energy are the traditional sources of energy that a great number of people are familiar with. Wood and coal are examples of traditional energy sources.
Answer: Natural gas is regarded as an excellent fuel since it has a high calorific value and burns with a smokeless flame, producing no hazardous fumes.
Domestic gas cylinders like Indane contain mainly …… Answer: Butane
Answer: CNG these days is being used as a fuel in transport vehicles which results in lesser air pollution.
Answer: The two most important uses of natural gas are as follows: It is utilised as a fuel in thermal power plants and transportation vehicles.
Answer: Butane is the component which is found in natural gas as well as in biogas.
a) petroleum gas? b) natural gas? Answer: a) The main constituent of petroleum gas is butane b) The main constituent of natural gas is methane
Answer: a) Full form of LPG is Liquefied Petroleum Gas b) Full form of CNG is Compressed Natural Gas
Answer: Compressed Natural Gas is used in transport vehicles such as cars and buses.
Answer: Liquefied petroleum gas is composed of butane with smaller amounts of propane and ethane.
Answer: Petroleum gas, diesel, kerosene, and petrol are the fractions derived from petroleum that are used as fuels.
Answer: Coal, gas, and oil are the different fuels utilised in the generation of electricity in a thermal power station.
Answer: Kerosene is a hydrocarbon fraction derived by fractional distillation of petroleum and used as a household fuel.
Answer: Liquified Petroleum Gas is an example of a good domestic fuel.
Answer: The product of petroleum that is used to drive heavy vehicles is Diesel.
a) coal b) petroleum gas c) biogas d) natural gas Answer: c) biogas Biogas is a renewable source while rest are non-renewable
a) high calorific value b) no emission of smoke c) smooth burning d) high ignition temperature Answer: d) high ignition temperature High ignition temperature leads to system instability and...
a) more of carbon but less of hydrogen b) less of carbon but more of hydrogen c) equal proportions of carbon and hydrogen d) less of carbon as well as less of hydrogen Answer: b) less of...
a) coal b) wood c) charcoal d) kerosene Answer: b) wood
a) natural gas b) methane gas c) hydrogen gas d) biogas Answer: c) hydrogen gas
a) 50 years b) 25 years c) 45 years d) 15 years Answer: d) 15 years
a) biogas b) methane gas c) hydrogen gas d) natural gas Answer: b) methane gas
a) high calorific value and low ignition temperature b) high calorific value and high ignition temperature c) high calorific value and moderate ignition temperature d) low calorific value and...
a) wind b) flowing water c) fossil fuels d) fuel wood Answer: c) fossil fuels Fossil fuels once exhausted can not be replenished.
a) wood b) alcohol c) hydrogen gas d) natural gas Answer: d) Natural gas Natural Gas once exhausted can not be replenished.
a) petrol b) natural gas c) biogas d) kerosene Answer: c) biogas Only biogas is replenishable.
Answer: Fuel-A i) It has a low calorific value of 55kJ/g, which is a drawback. ii) The ignition temperature is 80°C, which is moderate and advantageous. iii) No hazardous gases are created, which is...
b) What are the characteristics of an ideal fuel or good fuel? Answer: a) A fuel is a material that is burned to generate heat energy. The five types of fuels are wood, LPG, coal, kerosene, and...
Answer: Because coal takes longer to accumulate than growing trees, it is regarded a non-renewable source of energy. Whereas wood is considered a renewable source of energy. As a result, utilising...
Coal, wind, tides, petroleum, wood , natural gas b) What is the basis of above classification? Answer: Wind, tides, and wood are examples of renewable energy sources. Coal, petroleum, and natural...
Answer: Petroleum and coal are the only non-renewable sources of energy. This is due to the fact that they cannot be reclaimed once they have been fully utilised.
Answer: Air and water are renewable energy sources since they are abundant in nature and may be used repeatedly.
Answer: Fossil fuels are classified as non-renewable source of energy since once these are used completely these cannot be replenished.
Answer: The difference between a renewable and a non-renewable energy source is that a renewable energy source is abundant in nature, but a non-renewable energy source is finite. Overuse of...
Answer: A renewable energy source is described as a source of energy that is abundant in nature and may be used for an indefinite amount of time; it never runs out. Solar and wind energy are two...
Answer: A non-renewable energy source is described as one that will deplete rapidly if used for an extended length of time. These energy sources are only found in small amounts in nature. Coal and...
Answer: The following four properties will characterise a good source of energy: a) It's simple to store and move. b) The energy is simple to handle and secure. d) There is a lot of energy...
Answer: A source of energy is one from which a sufficient amount of energy can be obtained over an extended period of time. The two primary categories of energy sources are as follows: a) Renewable...
The amount of heat produced by burning a unit mass of a fuel completely is known as its ………. value. Answer: Calorific value.
Answer: When a fuel's ignition temperature is 80 degrees Celsius, it signifies that the fuel's lowest temperature for catching fire and burning is 80 degrees Celsius.
Answer: A fuel's ignition temperature is defined as The minimal temperature at which it must be heated in order to catch fire and begin burning.
Answer: A fuel's ignition temperature is defined as the minimal temperature at which it must be heated in order to catch fire and begin burning.
Coal or LPG Answer: Because LPG has a larger calorific value than coal, it will create more heat per unit mass when burned.
Answer: Cooking gas has a calorific value of 50kJ/g, which indicates that if 1 gramme of LPG is totally burned,...
Answer: The quantity of heat produced by totally burning 1 gramme of fuel is referred to as the calorific value of the fuel.
Answer: Other than fossil fuels, nuclear fuels such as uranium are a non-renewable source of energy.
a) methane b) ethane c) butane d) propane Answer: The correct answer is c) butane
a) methane b) ethane c) propane d) butane Answer: The correct answer is a) methane
a) nitrogen oxides b) sulphur oxides c) sodium oxides d) carbon oxides Answer: The correct answer is c) sodium oxides
a) petrol b) kerosene c) petrol d) CNG Answer: The correct answer is c) petrol
a) diesel b) kerosene c) petrol d) CNG Answer: The correct answer is b) kerosene
a) moon b) earth c) sun d) sea Answer: The correct answer is c) sun
a) kerosene oil b) cow-dung cakes c) CNG d) coal Answer: The correct answer is b) cow-dung cake
a) coal b) uranium c) natural gas d) fuel oil Answer: The correct answer is b) uranium
a) butane b) ethane c) butanone d) methane Answer: The correct answer is a) butane
a) as a fuel for industrial boilers b) as an oxidizing agent c) as a reducing agent d) as a fuel in domestic ovens Answer: The correct answer is c) as a reducing agent
a) coal gas b) electricity c) oil d) charcoal Answer: The correct answer is d) charcoal
a) nitrogen monoxide b) sulphur dioxide c) carbon monoxide d) carbon dioxide Answer: The correct answer is c) carbon monoxide
a) a sunny day b) a cloudy day c) a hot day d) a windy day Answer: The correct option is b) a cloudy day
a) kinetic energy possessed by stored water is converted into electrical energy b) electricity is extracted from water c) water is converted into steam to turn turbines and produce electricity d)...
a) plane mirror reflector b) black coating inside the box c) glass sheet cover d) utensils placed in the cooker box Answer: The correct option is c) glass sheet cover
a) conductors b) insulators c) semiconductors d) superconductors Answer: The correct option is c) semiconductors
a) 1.4kWh b) 1.4kW/m c) 1.4kW/m2 d) 1.4kW/m3 Answer: The correct option is c) 1.4kW/m2
a) visible light rays b) ultraviolet rays c) cosmic rays d) infrared rays Answer: The correct option is d) infrared rays
a) transparent plastic sheet b) shining aluminum sheet c) butter paper sheet d) transparent glass sheet Answer: The correct option is d) transparent glass sheet
a) 15km/h b) 25km/h c) 35km/h d) 45km/h Answer: The correct option is a) 15km/h
The correct option is c) 5040kJ Given that $\begin{array}{l}\text { Solar constant }=1.4 \mathrm{~kW} / \mathrm{m}^{2}=1.4 \mathrm{~kJ} / \mathrm{s} / \mathrm{m}^{2} \quad\left(\text { converted }...
a) the solar cooker is not placed in the shade b) the glass sheet cover of solar cooker is not closed c) a convex mirror reflector is not used d) the food containers of insulating material are not...
a) wood b) biogas c) atomic energy d) cow-dung Answer: The correct option is c) atomic energy
a) wind energy b) geothermal energy c) fossil fuels d) ethane Answer: The correct option is b) geothermal energy
a) butane b) methane c) propane d) ethane Answer: The correct option is b) methane
a) hydrogen b) butane c) hydrogen sulphide d) methane Answer: The correct option is d) methane
a) burning of diesel b) burning of coal c) burning of charcoal d) burning of wood Answer: The correct option is c) burning of charcoal
a) solar cells b) windmills c) nuclear power d) tidal power Answer: The correct option is c) nuclear power
a) sun b) earth c) moon d) mars Answer: The correct option is c) moon
a) cow-dung b) water c) oxygen d) anaerobic bacteria Answer: The correct option is c) oxygen
a) firewood b) cow-dung cakes c) coke d) charcoal Answer: The correct option is c) coke
a) hydroelectricity b) sewage gas c) natural gas d) gobar gas Answer: The correct option is c) natural gas\
a) fission of radioactive materials b) burning of coal inside the coal mines c) combustion of natural gas deep inside the earth d) fusion of radioactive substance Answer: The correct option is a)...
a) thermal power b) tidal power c) hydro power d) geothermal power Answer: The correct option is c) hydro power
a) displacement of people b) production of methane c) occurrence of floods d) ecological disturbance Answer: The correct option is c) occurrence of floods
a) liquid sodium b) boron c) graphite d) carbon dioxide Answer: The correct option is c) graphite
a) steel b) graphite c) uranium d) boron Answer: The correct option is d) boron
a) liquid mercury and nitrogen dioxide b) liquid sodium and carbon dioxide c) liquid ammonia and carbon monoxide d) liquid boron and uranium oxide Answer: The correct option is b) liquid sodium and...
a) which cools the hot, spent steam to condense it back to water b) which transfers heat from reactor to water in heat exchanger c) which is boiled to make steam to turn the turbine d) which cools...
a) wind energy b) nuclear energy c) biomass energy d) ocean thermal energy Answer: The correct option is b) nuclear energy
a) 931 eV b) 9.31 MeV c) 1 MeV d) 931 MeV Answer: The correct option is d) 931 MeV
a) nuclear diffusion b) nuclear fission c) nuclear fusion d) nuclear fermentation Answer: The correct option is b) nuclear fission
a) 1.6 × 10-14 J b) 1.6 × 10-12 J c) 1.6 × 10-19 J d) 1.6 × 10-13 J Answer: The correct option is c) 1.6 × 10-19 J
a) protons b) deuterons c) electrons d) neutrons Answer: The correct option is d) neutrons
a) atom bomb b) power plants c) sun d) pacemaker Answer: The correct option is c) sun
a) 9 × 1016 J b) 9 × 1014 J c) 9 × 1015 J d) 9 × 1013 J Answer: The correct option is d) 9 × 1013 J
a) conversion of hydrogen gas into helium b) conversion of carbon fuel into carbon dioxide c) burning of hydrogen gas present in the sun d) disintegration of uranium into barium and krypton Answer:...
a) nuclear power plant b) hydrogen bomb c) thermal power station d) atom bomb Answer: The correct answer is d) atom bomb
a) 1.6 × 10-13 J b) 1.6 × 10-19 J c) 1.6 × 10-16 J d) 1.6 × 10-15 J Answer: The correct option is a) 1.6 × 10-13 J Explanation: When an electron with a charge of 1.6 × 10-19 J Coulomb is accelerated...
a) ocean thermal energy b) nuclear fusion energy c) geothermal energy d) nuclear fission energy Answer: The correct option is b) nuclear fusion energy
a) too heavy b) highly inflammable c) extremely foul smelling d) highly radioactive Answer: The correct option is d) highly radioactive
a) conversion of stored chemicals into energy b) conversion of momentum into energy c) conversion of mass into energy d) conversion of magnetism into energy Answer: The correct option is c)...
a) uranium b) deuterium c) barium d) krypton Answer: The correct option is b) deuterium Deuterium is formed by the fusion of two Hydrogen atoms.
a) hydrogen as fuel b) biomass energy c) ocean energy d) fossil fuels Answer: The correct option is d) fossil fuels. Burning of fossil fuels results in the release of many harmful...
a) 200 years b) 400 years c) 500 years d) 100 years Answer: The correct option is a) 200 years
a) coal b) uranium c) petroleum d) natural gas Answer: The correct answer is c) petroleum because petroleum is a non renewable resource and it can't be replenished once exhausted...
a) DLF b) CFL c) FCL d) LPG Answer: The correct option b)...
Solution: (a) Non-metals are materials that conduct electricity poorly and are neither malleable nor ductile. Carbon, sulphur, phosphorus, silicon, and oxygen are some examples. (b) Carbon is a good...
Hz is incident in a metal surface. Electrons with a maximum speed of 6.0 x 
m/s are ejected from the surface. What is the threshold frequency for photoemission of electrons?Frequency of the incident photon is given as $\mathbf{v}=488 \mathrm{~nm}=488 \times 10^{-9} \mathrm{~m}$Maximum speed of the electrons is given as $\mathbf{v}=6.0 \times 10^{5} \mathrm{~m} /...
Work function of the metal is given as $\Phi_{o}=4.2 \mathrm{eV}$Charge on an electron, $\mathrm{e}=1.6 \times 10^{-19} \mathrm{C}$Planck's constant, $\mathrm{h}=\mathbf{6} .626 \times 10^{-34}...
Power of the sodium lamp is given as $\mathbf{P}=\mathbf{1 0 0 W}$Wavelength of the emitted sodium light is given as $\lambda=589 \mathrm{~nm}$$$=589 \times 10^{-9} \mathrm{~m}$$Planck's constant,...
exists in a cylindrical region of a radius of 
, its direction parallel to the axis along east to west. A wire carrying a current of 
A in the north to south direction passes through this region. What is the magnitude and direction of the force on the wire if, the wire in the N-S direction is lowered from the axis by a distance of 
When the wire is lowered by $6 \mathrm{~cm}$, then Then, $x=\sqrt{(10)^{2}-\left(6^{2}\right)}=\sqrt{64}=8 \mathrm{~cm}$ $2 \mathrm{x}=\mathrm{I}_{2}=16 \mathrm{~cm}$ $F_{2}=BII_{2}$=$1.5 \times 7...
Because of the electric field, the negatively charged electron tends to go towards the north. The electron will not be deflected if an equal magnetic force acts in the other direction. We derive the...
and outer radius 
, around which 3500 turns of a wire are wound. If the current in the wire is 
, what is the magnetic field in the empty space surrounded by the toroid.The magnetic field in the empty space surrounded by the toroid is zero as it is non-ferromagnetic.
. Find the kinetic energy at which (a) an electron, and (b) a neutron, would have the same de Broglie wavelength.Wavelength of light of a sodium line is given as $\lambda=589 \mathrm{~nm}=589 \times 10^{-9} \mathrm{~m}$ Mass of an electron, $\mathrm{m}_{\mathrm{e}}=9.1 \times 10^{-31} \mathrm{Kg}$ Mass of a...
de Broglie wavelength of an electron having a momentum $p$, is given by the relation: $\lambda=\frac{h}{p}$ $=\frac{6.6 \times 10^{-34}}{5.91 \times 10^{-24}}=1.116 \times 10^{-10} \mathrm{~m}=0.112...
Kinetic energy of the electron is given as $\mathbf{E}_{\mathrm{K}}=\mathbf{1 2 0} \mathrm{eV}$ Planck's constant, $\mathbf{h}=\mathbf{6 . 6} \times \mathbf{1 0}^{-34} \mathrm{~J} \mathrm{~s}$ Mass...
.Potential difference is given in the question as $\mathbf{V}=\mathbf{5 6 V}$ Planck's constant, $\mathbf{h}=6.6 \times 10^{-34} \mathrm{~J} \mathrm{~s}$ Mass of an electron, $\mathbf{m}=\mathbf{9 ....
is produced by an argon laser which is used in the photoelectric effect. When light from this spectral line is incident on the emitter, the stopping (cut-off) potential of photoelectrons is 
. Find the work function of the material from which the emitter is made.Wavelength of light produced by the argon laser is given as $\lambda=488 \mathrm{~nm}=488 \times 10^{-9} \mathrm{~m}$ Stopping potential of the photoelectrons is given as...
is incident in a metal surface. Electrons with a maximum speed of 
are ejected from the surface. What is the threshold frequency for photoemission of electrons?Frequency of the incident photon is provided as $v=488 \mathrm{~nm}=488 \times 10^{-9} \mathrm{~m}$ Maximum speed of the electrons is $\mathbf{v}=\mathbf{6 . 0} \times \mathbf{1 0}^{5} \mathrm{~m} /...
Will this metal give photoelectric emission for incident radiation of wavelength 330 nm?Work function of the metal is given as $\Phi_{o}=4.2 \mathrm{eV}$ Charge on an electron is $\mathbf{e}=\mathbf{1 . 6} \times \mathbf{1 0}^{-19} \mathbf{C}$ Planck's constant, $\mathbf{h}=\mathbf{6 ....
. If the light of frequency 
is incident on the metal, predict the cut-off voltage for the photoelectric emission.Threshold frequency of the metal given to us is $\mathbf{v}_{\mathbf{0}}=\mathbf{3 . 3} \times \mathbf{1 0}^{\mathbf{1 4}} \mathrm{Hz}$. Frequency of light incident on the metal is given as...
sodium lamp radiates energy uniformly in all directions. The lamp is located at the centre of a large sphere that absorbs all the sodium light which is incident on it. The wavelength
(a) What is the energy per photon associated with the sodium light? (b) At what rate are the photons delivered to the sphere?Power of the sodium lamp is given as $\mathbf{P}=\mathbf{1 0 0 W}$ Wavelength of the emitted sodium light is given as $\lambda=589 \mathrm{~nm}$ $=589 \times 10^{-9} \mathrm{~m}$ Planck's constant,...
Calculate the value of Planck’s constant.The slope of cut-off voltage (V) versus frequency (v) is given as, $\frac{V}{v}=4.12 \times 10^{-15} \mathrm{Vs}$ $\mathrm{V}$ and frequency is related by the equation: $\mathrm{Hv}=\mathrm{eV}$...
. How many photons are incident on the Earth per second/square meter? Assume an average wavelength of 
Energy flux of sunlight reaching the surface of the earth: $\phi=1.388 \times 10^{3} \mathrm{~W} / \mathrm{m}^{2}$ Hence, power of sunlight per square metre, $\mathbf{P}=\mathbf{1 . 3 8 8} \times...
Identification: Ore A - Carbonate ore Steps to convert carbonate ore into metal: 1. Calcination - Metal oxide is obtained by heating the ore in the presence of oxygen. Reaction Involved: ACO3→ AO+...
Identification: A - Sodium B - Chlorine C - Sodium Chloride D - Sodium hydroxide Reactions Involved: 2Na +CL2 →2NaCl 2NaCl+ 2H2O→ 2NaOH+ Cl2+H2
Identification: X - Sodium Y - Magnesium Z – Iron Reactions Involved: Na + H₂O → 2NaOH + H₂ Mg + H₂O → Mg(OH)₂ + H₂ Fe + H₂O → Fe₂O₃+ H₂ Arrangement of the metals in order of...
(a) Roasting of copper (1) sulphide (b) Reduction of copper (1) oxide with copper (1) sulphide. (c) Electrolytic refining (ii) Draw a neat and well-labelled diagram for electrolytic refining of...
(a) Reactivity of Al decreases if it is dipped in HNO3 (b) Carbon cannot reduce the oxides of Na or Mg (c) NaCl is not a conductor of electricity in the solid-state whereas it does conduct...
The steps involved in the extraction of metals of low and medium reactivity from their respective sulphide ores are heating the ores in the presence of oxygen to produce the oxides of the metal....
(a) Identify A, B, C and D (b) To which group of periodic table does this non-metal belong? Answers: (a) A - Nitrogen Explanation: Nitrogen is the non-metal which is the largest constituent of...
FeSO4 is produced when iron displaces the copper which makes the reactivity of iron higher than that of copper. And this nature of iron is responsible for the holes in the pot. Reaction Involved:...
Identification of the element A is a non-metal as they their oxides are usually acidic.
A - Sodium B - Sodium Hydroxide C - Sodium Aluminate Reaction Involved: Al2O3 +2NaOH →2NaAlO2+H2O
Identification: Metal M - Copper Black colored product - copper oxide Reaction Involved: 2Cu+ O2 →2CuO
Reactions involved during the extraction of zinc from its ore by, (a) Roasting of zinc ore: 2ZnS + 3O2→2ZnO + 2SO2. (b) Calcination of zinc ore: ZnCo3→ZnO+CO
A - Calcium B - Calcium Hydroxide C - Calcium Oxide Reactions Involved: Ca+2H2O →Ca(OH)2+ H2 Ca(OH)2 →CaO+H2O CaO+H2O→ Ca(OH)2
Mercury and Bromine exists in a liquid state at room temperature; Caesium and Gallium has a melting point less than 310 K (37°C).
Examples of good conductors are Iron and Copper. Examples of bad conductors are Lead and Mercury.
(a) Identify A, B and C (b) To which Group of Periodic Table does A belong? Answers: (a) A - Carbon B - Carbon monoxide C - Carbon-dioxide (b) Group...
(a) ZnCO3 is heated in the absence of oxygen? (b) a mixture of Cu2O and Cu2S is heated? Answers: (a) Carbon-di-oxide are liberated Reaction: ZnCo3 →ZnO + CO2 (b) Pure Copper is obtained...
(a) Mg and N2 (b) Li and O2 (c) Al and Cl2 (d) K and O2 Answers: (a) Magnesium Nitride (Mg3N2) (b) Lithium Oxide( Li2O) (c) Aluminium Chloride( AlCl3) (d) Potassium Oxide (...
Mercury is the metal that exists as a liquid at room temperature is obtained by heating its sulphide in the presence of air. Cinnabar is the ore of mercury. Reaction: 2HgS + 3O2→ 2HgO +...
Metal A - Aluminium (Al) Metal B – Aluminium Oxide (Al2O3 ) With HCl, the following reaction occurs: Al2O3+ 6HCl →2AlCl3+3H2O With NaOH, the following reaction occurs: Al2O3+2NaOH...
Constituents of solder - Lead and aluminium. The low melting point of this alloy makes it fit for the welding of electrical wires.
3 MnO2 (s) + 4 Al (s) → 3 Mn (l) + 2 Al2O3 (l) + Heat (a) Is aluminium getting reduced? (b) Is MnO2 getting oxidised? Answer: Aluminium gets oxidized when oxygen is combined and MnO2 gets...
Identification: X – Carbon Y – Diamond Z – Graphite
Identification: X - Sodium (Na) Y - Sodium Hydroxide (NaOH) Z - Hydrogen gas Reaction Involved: 2Na+2H2O → 2NaOH+H2
(a) Compound X - Fe2O3 (b) Aluminothermy (c) Fe2O3(s) + 2Al(s)→ Al2O3 (s) + 2Fe(s)
HNO3 which is a strong oxidizing agent, oxidises the liberated Hydrogen into the water and converts itself into nitrogen oxide.
(a) Na (b) Ca (c) Al (d) Cu Answer: (c) Al Reason: Aluminum oxide exhibits both acidic and basic performance which is why it is an amphoteric oxide.
Usually, metals can be obtained easily in oxide form than in its sulphide or carbonate form and because of this reason metal sulphides and carbonated must be converted to metal oxides in the metal...
(a) Anode - Impure metal; Cathode - Pure metal (b) Electrolyte - Silver Sulphate/Silver Nitrate (c) Cathode
The lighted matchstick must be brought close to the gas to identify the produced gas. When the stick burns a pop sound is observed which will help for the identification of the gas. Chemical...
Answer: (b) Explanation: The figure in option (b) properly shows the correct process of the electrolytic refining.
(a) Sulphur (b) Graphite (c) PVC (d) All can be used Answer: (c) PVC Reason: Insulators are materials that do not allow electrical energy to flow. Therefore, insulators are used to cover electrical...
(a) MgSO4 + Fe (b) ZnSO4 + Fe (c) MgSO4 + Pb (d) CuSO4 + Fe Answer: (d) CuSO4 + Fe Reason: The reactivity of Iron is more than copper which is why it transmits copper in response...
(a) Diamond (b) Graphite (c) Sulphur (d) Fullerene Answer: (b) Graphite Reason: Normally non-metals do not transmit heat and electricity, however, graphite is different. Graphite (an allotropic form...
(a) Carbon (b) Bromine (c) Phosphorus (d) Sulphur Answer: (b) Bromine Reason: Physically most of the non-metallic material around us exists as gases, solid brittle. For example, hydrogen, oxygen...
(a) X is a metal (b) Y is a metal (c) Z is a non-metal (d) Y is a non-metal and Z is a metal Answer: (d) Y is a non-metal and Z is a metal Reason: Based on the electronic configuration of the...
(a) Has a high melting point (b) Has a low melting point (c) Conducts electricity in molten state (d) Occurs as solid Answer: (b) Has a low melting point Reason: X is a metal that is electropositive...
(a) Stainless steel (b) Alnico (c) Solder (d) Zinc amalgam Answer: (d) Zinc amalgam Reason: Zinc amalgam is a mixture of mercury (10%) containing zinc (90%). It contains mercury as one of its...
(a) It burns in oxygen with a dazzling white flame (b) It reacts with cold water to form magnesium oxide and evolves hydrogen gas (c) It reacts with hot water to form magnesium hydroxide and evolves...
(a) Brass (b) Bronze (c) Amalgam (d) Steel Answer: (d) Steel Reason: Iron in its purest form is very soft and rusts. Therefore, it is combined with another metal to change its properties. Iron mixed...
(a) Mg (b) Na (c) P (d) Ca Answer: (b) Na Reason: Sodium is an element that is soft and can be cut with a knife, reactive to air and cannot be kept open in the air and also reacts vigorously with...
(a) deposited on cathode (b) deposited on anode (c) deposited on the cathode as well as anode (d) remains in the solution Answer: (a) deposited on cathode Reason: During the process of refining of...
(i) positively charged cathode (ii) negatively charged anode (iii) positively charged anode (iv) negatively charged cathode (a) (i) and (ii) (b) (iii) and (iv) (c) (i) and (iii) (d) (ii) ad (iv)...
(a) an element (b) a compound (c) a homogeneous mixture (d) a heterogeneous mixture Answer: (c) a homogeneous mixture Reason: An alloy is a homogeneous mixture
(a) Al (b) Au (c) Cu (d) Pt Answer: (b) Au Reason: Gold is an insoluble metal in soluble acids and only soluble in aqua region. Therefore, the metal on the C test plate should be gold (Au). The...
Compound X - Sodium hydroxide A – Sodium Zincate Reaction: 2NaOH+ Zn→ Na₂ZnO₂ + H2(g) B – Sodium Chloride Reaction: NaOH + HCl →NaCl + H2O C – Sodium Acetate Reaction: NaOH + CH3 COOH→ CH3COONa +...
Plaster of Paris is calcium sulphate which is white in colour and has soft texture. 2. Gypsum is a hard compound which is used for molding purposes and is formed when Plaster of Paris is left open...
Identification: B – Sodium Hydroxide(NaOH) Neutralization process occurs when sodium hydroxide reacts with acidic oxide. 2NaOH+ CO2 →Na2CO3+ H2O
Identification: X - Calcium Y - Lime water G - Chlorine gas Z - Bleaching powder
how will it affect the taste of the cake and why?how can baking soda be converted into baking powder?what is the role of tartaric acid added to baking soda Answers: The cake will be bitter as...
1. In place of zinc granules, the same amount of zinc dust is taken in the test tube 2. Instead of dilute sulphuric acid, dilute hydrochloric acid is taken 3. In place of zinc, copper turnings are...
When zinc metal is treated with a dilute solution of a strong acid, hydrogen gas is evolved. Reaction: ...
Acids that can be completely ionized is called strong acids. Acids that can be partially ionized is called weak acid. 1. Hydrochloric acid is a Strong Acid 2. Citric acid is a Weak Acid 3. Acetic...
Name of the SaltFormulaBaseAcidAmmonium chlorideNH4ClNH4OH–Copper sulphate––H2 SO4Sodium chlorideNaClNaOH–Magnesium nitrateMg (NO3 ) 2–HNO3Potassium sulphateK2 SO4––Calcium nitrateCa(NO3 ) 2Ca(OH)2–...
Identification: X = Chlorine Y = Bleaching powder Reaction Involved: Ca(OH)2 (s) + Cl2 (g) → CaOCl2 (s) + H2O — Calcium oxychloride (bleaching powder)
Identification: Salt A - Baking soda Salt B - Sodium carbonate Gas C - CO2
When we heat baking powder, CO2 is released and when this gas is introduced into lime water the solution will turn milky. This reaction will not occur if you heat a washing soda.
The student can use phenopthalein indicator to identify which solution is acid and base.
When the egg shell is dissolved in nitric acid, the calcium carbonate present in the eggshell reacts with the nitric acid and produces calcium nitrate and carbon-di-oxide gas.
Methanoic acid is the acid present in ant sting and its chemical formula is HCOOH. Rubbing the affected place with baking soda can cause relief from the discomfort of ant sting.
1. Dry HCl gas- No effect 2. Moistened NH3 gas- litmus paper turns to blue colour 3. Lemon juice- litmus paper turns to red colour 4. Carbonated soft drink- litmus paper turns to blue colour 5....