Question

In the reaction C + 02 - CO2, 18 g of carbon react with oxygen to produce 72 g of carbon dioxide. What mass of oxygen would be needed in the reaction? O 18 g O 54 g O 72 g 0 90 g​

Answer 1

Mass of oxygen : 54 g

Further explanation

Conservation of mass applies to a closed system, where the masses before and after the reaction are the same

Reaction

$\tt C+O_2\rightarrow CO_2$

mass before reaction = mass after reaction

mass C + mass O₂= mass CO₂

$\tt 18~g+mass~O_2=72~g\\\\mass~O_2=72-18=\boxed{\bold{54~g}}$