Question

1. which of the following represents a violation of the law of conservation of mass? a. a piece of paper burning and turning into ash b. a glass of water gradually evaporating c. a chemical reaction in which the total mass of products is less than the total mass of reactants d. a candle melting and forming a puddle of wax

Explanation:

The Law of Conservation of Mass states that in a closed - system chemical reaction, the total mass of the reactants equals the total mass of the products. In option a, paper burning is a chemical reaction but mass is conserved when considering gases released. In option b, water evaporation is a physical change and mass is conserved as water vapor has mass. In option d, candle melting is a physical change and mass is conserved. Option c shows a situation where the total mass of products is less than reactants, which violates the law.

Answer:

C. A chemical reaction in which the total mass of products is less than the total mass of reactants