Question

HOW MANY MOLECULES ARE PRESENT IN 34g OF AMMONIA

Answer 1

The molar mass of nitrogen is 14 g while that of hydrogen is 1g. The chemical formula for ammonia is NH₃, so the molar mass of ammonia will be

= molar mass of nitrogen + 3 X (molar mass of hydrogen)

= 14 + 3 X (1) = 17 g

Thus the molar mass of ammonia is 17 g. This means that there are 6.023 X 10²³ molecules of ammonia present in 17 g of ammonia. That is

17 g of NH₃ = 6.023 X 10²³ molecules of ammonia

So 1 g of NH₃ = ( 6.023 X 10²³ / 17 ) molecules of ammonia

and 34 g of NH₃ = ( 6.023 X 10²³ X 34 ) / 17 molecules of ammonia

= 1.2046 X 10²⁴ molecules of ammonia

Thus there are 1.2046 X 10²⁴ molecules of ammonia in 34 g of ammonia