Question

The weight of 2.01 x 1023 molecules of co is

Answer 1

1 mole of ammonia is sum of atomic masses = 14 +3 = 17g

by definition 1 mole of any gas contains 6.02 x 10(23) molecules of NH3

So

6.02 x 10(23) molecules of NH3 weigh 17g

1x 10(23) molecules of NH3 weigh 17/6.02g

2.6x 10(23) molecules of NH3 weigh 2.6 x 17/6.02g

Presumably you can take it from there and check on a calculator that it gives 7.36g

Answer 2

1 mole of ammonia is sum of atomic masses = 14 +3 = 17g

by definition 1 mole of any gas contains 6.02 x 10(23) molecules of NH3

So

6.02 x 10(23) molecules of NH3 weigh 17g

1x 10(23) molecules of NH3 weigh 17/6.02g

2.6x 10(23) molecules of NH3 weigh 2.6 x 17/6.02g

Presumably you can take it from there and check on a calculator that it gives 7.36g