Question

What amount (moles) is represented by each of these samples? (a) 22.5 mg lye, NaOH mol (b) 2.57x1021 molecules of chalk, CaCO3 mol (c) 1.46 g of sucrose, C12H22011 mol

Answer 1

a) 0.0005625 moles NaOH

b) 0.00427 moles CaCO3

c) 0.00427 moles sucrose

Step-by-step explanation:

(a) 22.5 mg lye, NaOH mol

Moles = mass / molar mass

Moles = 0.0225 grams / 40 g/mol

Moles = 0.0005625 moles NaOH

(b) 2.57*10^21 molecules of chalk, CaCO3 mol

Moles = molecules / number of Avogadro

Moles = 2.57*10^21 / 6.022*10^23

Moles = 0.00427 moles CaCO3

(c) 1.46 g of sucrose, C12H22011 mol

Moles = 1.46 grams / 342.3 g/mol

Moles = 0.00427 moles sucrose