Question

report sheet
lab
moles and chemical formulas
11
a. finding the simplest formula

1. mass of empty crucible + cover

26.918

1. initial appearance of the magnesium

shiny

1. mass of crucible + cover + magnesium

27.079

1. mass of crucible + cover + oxide product

calculations

1. mass of magnesium

0.161

1. mass of magnesium compound
2. mass of oxygen in the product
3. moles of mg

(show calculations.)

1. moles of o

(show calculations.)

Explanation:

Step1: Calculate mass of magnesium

Mass of magnesium = Mass of crucible + cover + magnesium - Mass of empty crucible + cover
$=27.079 - 26.918=0.161$ g

Step2: Calculate moles of Mg

Molar mass of Mg is $24.305$ g/mol.
Moles of Mg $=\frac{\text{Mass of Mg}}{\text{Molar mass of Mg}}=\frac{0.161}{24.305}\approx6.63\times10^{-3}$ mole

Answer:

Moles of Mg is approximately $6.63\times10^{-3}$ mole.