MCQ
Laws of Chemical Combination
By Sakshi Goel | 18 May'20 | 1 K Views
MCQ
Problem:
Solution:
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Phosphorus forms two oxides P2O3 and P2O5. Which law can be proved by the weights of P and O?
(a) Constant composition
(b) Multiple proportions
(c) Gay Lussac law
(d) Conservation of mass
Solution:
The law of multiple proportions can be proved by the weights of P and O in these two compounds.
Atomic mass of P is 31 g/mol
Atomic mass of O is 16 g/mol.
In P2O3, 62 parts of P combines with 48 parts of O.
In P2O5, 62 parts of P combines with 80 parts of O.
The ratio of O in both compounds is 48:80 or 3:5 which is a simple whole number ratio.
This proves the law of multiple proportions.
So, correct option is (b).
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