Which expression represents the percent by mass of nitrogen in nh4no3?

This question is incomplete. The completed question is below

Which expression represents the percent by mass of nitrogen in NH4NO3?

A) 14 g N/80 g NH₄ NO₃ ₓ 100%

B) 28 g N/80 g NH₄ NO₃ ₓ 100%

C) 80 g NH₄ NO₃ /14 g N ₓ 100%

D) 80 g NH₄ NO₃ /28 g N ₓ 100%

The correct option is B

Explanation:

To calculate the percentage by mass of nitrogen in the compound, the formula will be

total mass of nitrogen/total mass of compound    × 100

Atomic mass of nitrogen (N) is 14 g/mol

There are 2 nitrogen atoms present in the compound as highlighted below

Total mass of nitrogen (N) present in NH₄ NO₃ = 14 × 2 = 28g

Atomic mass of hydrogen (H) is 1 g/mol. There are 4 hydrogen atoms present in the compound, NH₄NO₃.

Atomic mass of oxygen (O) is 16 g/mol. There are 3 oxygen atoms present in the compound, NH₄NO₃

Total mass of the compound =

(14 × 2) + (1 ×4) + (16 × 3) = 80g

Hence, the percentage by mass of nitrogen in the compound (as shown in the formula earlier) is

28g of N/80g of NH₄NO₃ × 100%

let that person have a turn to speak : )

the answer is c. nacl