Answer:
0.192 mol.
Step-by-step explanation:
- To calculate the no. of moles of a substance (n), we use the relation:
n = mass / molar mass.
mass of AsH₃ = 15.0 g.
molar mass of AsH₃ = 77.95 g/mol.
∴ The number of moles in 15.0 g AsH₃ = mass / molar mass = (15.0 g) / (77.95 g/mol) = 0.192 mol.