Final answer:
The total mass of the products (carbon dioxide and water) after the combustion of the hydrocarbon is equal to the sum of the mass of the hydrocarbon and oxygen that reacted, thereby confirming the law of conservation of mass.
Step-by-step explanation:
The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction. To show that the combustion of a hydrocarbon agrees with this law, we can compare the total mass of reactants with the total mass of products. In the given problem, 0.44 g of hydrocarbon was burnt completely to give 0.88 g of carbon dioxide and 1.8 g of water.
Combustion Reaction: Hydrocarbon (CxHy) + O2 → CO2 + H2O
Now, let's add the masses: Mass of CO2 (0.88 g) + Mass of H2O (1.8 g) = 2.68 g
The initial mass of the hydrocarbon was 0.44 g. To obey the law of conservation of mass, the mass of oxygen that reacted must have been 2.68 g - 0.44 g = 2.24 g. This shows that the total mass of reactants (hydrocarbon + oxygen) equals the total mass of products (carbon dioxide + water).