Question

What is the percentage composition of each element in carbon dioxide, CO2? Remember percent composition is based on mass. (Show your calculations for full credit.)

Answer 1

%C = 27.3%

%O=72.7%

Further explanation

Proust states the Comparative Law that compounds are formed from elements with the same Mass Comparison, so that compounds have a fixed composition of elements

The empirical formula is the mole ratio of compounds forming elements.

MW CO₂ : 44 g/mol

Ar C = 12 g/mol

Ar O = 16

• %C

$\tt \dfrac{12}{44}\times 100\%=27.3\%$

• %O

$\tt \dfrac{2.16}{44}\times 100\%=72.7\%$