Source: Extra Practice

The law of multiple proportions is illustrated by which pair of compounds?

Options

Option A

NaCl and NaBr

Option B

H2O and D2O

Option C is correct

CO and CO2

Option D

MgO and Mg(OH)2

Explanation

The Law of Multiple Proportions states that if two elements combine to form more than one compound, the masses of one element that combine with a fixed mass of the other are in a ratio of small whole numbers. Carbon and Oxygen form CO and CO2. In CO, 12g C reacts with 16g O. In CO2, 12g C reacts with 32g O. The ratio of oxygen (16:32) is 1:2. NaCl/NaBr involve different elements (Cl vs Br). H2O/D2O involve isotopes.