Question

the law of conservation of mass can be demonstrated by a chemical reaction. which of the following models of a chemical reaction best represents the law of conservation of mass?

Explanation:

The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction. This means the number of each type of atom on the reactant side must equal the number on the product side.

• Option A:

Count the atoms. On the reactant side, there are \(2\) dark - colored atoms and \(3\) light - colored atoms. On the product side, there are \(2\) dark - colored atoms and \(3\) light - colored atoms.

• Option B:

On the reactant side, there is \(1\) light - colored atom and \(2\) dark - colored atoms. On the product side, there is \(1\) light - colored atom and \(1\) dark - colored atom. The number of dark - colored atoms is not conserved.

• Option C:

The color change of the central atom in the product (compared to the reactant dark - colored atom) is an issue. In a chemical reaction model for conservation of mass, the type of atom (represented by color) should be conserved.

• Option D:

On the reactant side, there is \(1\) dark - colored atom and \(2\) light - colored atoms (in the \(O_2\) - like structure). On the product side, there is \(1\) central atom (a different color, which is not in line with atom conservation in terms of type as represented by color in these models) and \(2\) light - colored atoms.

Answer:

A.