In the reaction C + O2 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?

18 g

549

729

90g

54 g

Explanation: The reaction between carbon and oxygen gas is given by the equation;

C (s) + O₂ (g) → CO₂ (g)

We are given;

18 g of Carbon

72 g of Carbon dioxide

We need to calculate the amount of oxygen needed for the reaction. From the law of conservation of mass in chemical equation, the mass of the reactants is equal to the mass of the product.

Therefore;

Mass of Oxygen gas + mass of the carbon = Mass of carbon dioxide

Therefore;

Mass of Oxygen gas = mass of carbon dioxide - mass of carbon

= 72 g - 18 g

= 54 g

Therefore, the mass of Oxygen needed would be 54 g