Question

34 g of ammonia is decomposed to _________ g of nitrogen and _____ g of hydrogen, _____ is the ratio of hydrogen to nitrogen by mass. The options in blanks are respectively:

• A. 28,3 and 28:3
• B. 14,6 and 14:6
• C. 14,3 and 14:3
• D. 28,6 and 14:3

Answer 1

The correct option is D

28,6 and 14:3

34 g of ammonia is decomposed to 28 g of nitrogen and 6 g of hydrogen, 14:3 is the ratio of hydrogen to nitrogen by mass.

Atomic masses of nitrogen and hydrogen are 14, 1 respectively.

Since there are three hydrogen atoms, total mass of hydrogen atoms is 3.

So the mass ratio is (Nitrogen):(Hydrogen) = 14:3

Total mass of compound is 34 (given).

The mass of nitrogen is $\frac{14}{17}\times 34\Rightarrow$ 28 g.

The mass of hydrogen is $\frac{3}{17}\times 34\Rightarrow$ 6 g.