Question

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
54g
72 g
90 g​

Answer 1

By the Law of chemical reaction of mass,

Mass can niether be created nor be destroyed in a chemcial reaction.

So, according to this question,

Mass of CO2 = 72g

mass of carbon =18g

By this law, Mass of oxygen = mass of co2 - mass of carbon

mass of oxygen = 72g-18g = 54 g

Therefore,Mass of oxygen is 54g