Question

What is the mass of a 3.23x10^25 atoms of ethane (C2H6)

Answer 1

1 molecule of ethane consists of 8 atoms. Therefore, the moles of etane equal:

$\frac{3.23•10^{25}}{6.02•10^{23}\times8}=6.7 mol$

The molar mass of ethane is 30.07 g/mol.

Therefore the mass is $30.07g/mol \times 6.7mol=201g$

Answer: 201 g