Question

1. a student performs a chemical reaction in an open system and finds that the mass of the products is less than the mass of the reactants. which of the following best explains the reason? matter was destroyed during the reaction, so the law of conservation of matter does not apply. a gas was produced and escaped from the open system, so the law of conservation of matter still holds. the reaction formed products with a lower density, which explains the loss in mass. some of the matter was converted into energy, violating the law

Explanation:

In a chemical reaction, the Law of Conservation of Matter holds in a closed - system. In an open - system, if the mass of products is less than reactants, it is likely that a gas was produced and escaped, carrying away some of the mass. Matter is not destroyed (by the Law of Conservation of Matter), and in normal chemical reactions, matter is not converted into energy (this occurs in nuclear reactions). Lower density of products does not explain the mass loss in terms of the Law of Conservation of Matter.

Answer:

A gas was produced and escaped from the open system, so the Law of Conservation of Matter still holds.