DPP -02 MOLE CONCEPT & STOICHIOMETRY (Mridul Pandey)
1. Chemical equation is balanced according to the law of.
A. Multiple proportion
B. Reciprocal proportion
C. Conservation of mass
D. Definite proportions
2. A water sample from a lake, ocean, rain or pond must have _____ proportions of
hydrogen to oxygen.
A. identical
B. different
C. similar
D. reciprocal
3. Which is an example of the law of multiple proportions?
A. CO and CO2
B. CO and H2 O
C. CO and CH4
D. CO and C2 H4
4. Which is an example of the law of multiple proportions?
A. CO and CO2
B. CO and H2 O
C. CO and CH4
D. CO and C2 H4
DPP -02 MOLE CONCEPT & STOICHIOMETRY (Mridul Pandey)
5. 1.0 g of an oxide of A contained 0.5 g of A. 4.0 g of another oxide of A contained 1.6 g of
A. The data indicate the law of
A. Reciprocal proportions
B. Constant proportions
C. Conservation of energy
D. Multiple proportions
6. 1.0 g of an oxide of A contained 0.5 g of A. 4.0 g of another oxide of A contained 1.6 g of
A. The data indicate the law of
A. Reciprocal proportions
B. Constant proportions
C. Conservation of energy
D. Multiple proportions
7. The percentage of copper and oxygen in samples of CuO obtained by different methods
were found to be the same. This illustrates the law of.
A. Constant proportions
B. Conservation of mass
C. Multiple proportions
D. Reciprocal proportions
8. Two samples of lead oxide were separately reduced to metallic lead by heating in a
current of hydrogen. The weight of lead from one oxide was half the weight of lead
obtained from the other oxide. The data illustrates
A. Law of reciprocal proportions
B. Law of constant proportions
C. Law of multiple proportions
D. Law of equivalent proportions
DPP -02 MOLE CONCEPT & STOICHIOMETRY (Mridul Pandey)
9. Different propartions of oxygen in the various oxides of nitrogen prove the
A. Equivalent proportion
B. Multiple proportions
C. Constant proportion
D. Conservation of matter
10. Carbon and oxygen combine to form two oxides, carbon monoxide and carbon dioxide in
which the ratio of the weights of carbon and oxygen is respectively 12 : 16 and 12 : 32.
These figures illustrate the
A. Law of multiple proportions
B. Law of reciprocal proportions
C. Law of conservation of mass
D. Law of constant proportions
11. Which of the following is the best example of law of conservation of mass
A. 12 g of carbon combines with 32 g of oxygen to form 44 g of CO2
B. When 12 g of carbon is heated in a vacuum there is no change in mass
C. A sample of air increases in volume when heated at constant pressure but its mass
remains unaltered
D. The weight of a piece of platinum is the same before and after heating in air
DPP -02 MOLE CONCEPT & STOICHIOMETRY (Mridul Pandey)
12. The law of multiple proportions is illustrated by the two compounds
A. Sodium chloride and sodium bromide
B. Ordinary water and heavy water
C. Caustic soda and caustic potash
D. Sulphur dioxide and sulphur trioxide
13. An element forms two oxides containing respectively 53.33 and 36.36 percent of oxygen.
These figures illustrate the law of
A. Conservation of mass
B. Constant proportions
C. Reciprocal proportions
D. Multiple proportions
14. After a chemical reaction, the total mass of reactants and products
A. Is always increased
B. Is always decreased
C. Is not changed
D. Is always less or more
15. A sample of pure carbon dioxide, irrespective of its source contains 27.27% carbon and
72.73% oxygen. The data support
A. Law of constant composition
B. Law of conservation of mass
C. Law of reciprocal proportions
D. Law of multiple proportions
DPP -02 MOLE CONCEPT & STOICHIOMETRY (Mridul Pandey)
16. Which one of the following pairs of compounds illustrates the law of multiple proportion
A. H2O,Na2O
B. MgO,Na2O
C. Na2O,BaO
D. SnCl2,SnCl4
17. Ammonia contains 82.65 % N2 and 17.65% H2. If the law of constant proportions is true,
then the mass of zinc required to give 10 g Ammonia will be:
A. 8.265 g
B. 0.826 g
C. 82.65 g
D. 826.5 g
18. Irrespective of the source, pure sample of water always yields 88.89% mass of oxygen
and 11.11% mass of hydrogen. This is explained by the law of:
A. conservation of mass
B. constant composition
C. multiple proportion
D. constant volume
19. A pure sample of ammonia contains 14 g of nitrogen and 3 grams of hydrogen. A second
sample of pure ammonia contains 28 g nitrogen and 6 g of hydrogen. This is an example
of the
A. law of universal gravitation
B. law of multiple proportions
C. law of definite proportions
D. Law of Mass action
