Hello there!

a sample of solid lithium carbonate decomposes to produce lithium oxide and carbon dioxide gas.

how many grams of carbon dioxide are produced when 12.5 grams of lithium carbonate completely
decompose?

Mass of carbon dioxide = 7.48 g

Explanation:

Given data:

Mass of lithium carbonate = 12.5 g

Mass of carbon dioxide produced = ?

Solution:

Chemical equation:

Li₂CO₃  →  Li₂O + CO₂

Number of moles of Li₂CO₃:

Number of moles = mass/ molar mass

Number of moles = 12.5 g /73.89 g/mol

Number of moles = 0.17 mol

Now we will compare the moles of Li₂CO₃  with CO₂.

                   Li₂CO₃        :            CO₂

                     1                :               1

                  0.17             :             0.17

Mass of carbon dioxide:

Mass of carbon dioxide = number of moles × molar mass

Mass of carbon dioxide =   0.17 mol ×  44 g/mol

Mass of carbon dioxide = 7.48 g