Question

Calculate the number of moles in 3.50 g of each of the following:

Express your answer with the appropriate units.

Au

SnO2

CS2

Ca3N2

C6H8O6, vitamin C

Answer 1

1) Au

Mass of Au = 3.5 g

Molar mass of Au = 196.97 g/mol

Number of mol of Au = mass/ molar mass = (3.5 g) / (196.97 g/mol) = 0.0178 mol

2) SnO₂

Mass of SnO₂ = 3.5 g

Molar mass of SnO₂ = 150.71 g/mol

Number of mol of SnO₂ = mass/ molar mass = (3.5 g) /(150.71 g/mol) = 0.0232 mol

3) CS₂

Mass of  CS₂ = 3.5 g

Molar mass of  CS₂ = 76.14 g/mol

Number of mol of CS₂ = mass/ molar mass = (3.5 g) /(76.14 g/mol) = 0.04597 mol

4) Ca₃N₂

Mass of  Ca₃N₂ = 3.5 g

Molar mass of  Ca₃N₂ = 148.25 g/mol

Number of mol of Ca₃N₂= mass/ molar mass = (3.5 g) /(148.25 g/mol) = 0.02360 mol

5) C₆H₈O₆ (Vitamin-C)

Mass of  C₆H₈O₆ = 3.5 g

Molar mass of C₆H₈O₆ = 176.12 g/mol

Number of mol of C₆H₈O₆ = mass/ molar mass = (3.5 g) /(176.12 g/mol) = 0.01987 mol