Question

What is the mass of a sample of NH3 containing 3. 80 × 10^24 molecules of NH3?

Answer 1

107g

Step-by-step explanation:

First convert the number of molecules to moles using avogadro's number.

There are 6.02 x 10^23 molecules in 1 mol.

3.8 x 10^24 molecules NH3 ÷ 6.02 x 10^23 molecules / mol

= 6.31 mol NH3

Now that we have moles of NH3 we can multiply it by NH3's molecular mass.

NH3 molecular mass = Mass of N + Mass of H x 3

14.007g/mol + 1.008g/mol * 3

= 17.031 g NH3/ mol

6.31 mol NH3 * 17.031 g NH3 / mol

= 107g NH3