Which of the following statements about the categories of chemical reactions is written correctly?

Question

Which of the following statements about the categories of chemical reactions is written correctly?

Decomposition reactions usually involve a change in the pH of a substance.

Decomposition reactions occur when two reactants combine to make a new product.

Energy is absorbed during a combustion reaction.

Synthesis reactions occur when two reactants combine to make a new product.

Answer 1

The statement that is written correctly is:

Synthesis reactions occur when two reactants combine to make a new product.

Here's a brief clarification on the other statements:

1. Decomposition reactions usually involve a change in the pH of a substance. - This statement is not necessarily correct as decomposition reactions do not inherently involve a change in pH; they involve breaking down a compound into simpler substances.

2. Decomposition reactions occur when two reactants combine to make a new product. - This statement is incorrect because decomposition reactions involve a single compound breaking down into two or more products, not combining.

3. Energy is absorbed during a combustion reaction. - This statement is incorrect because combustion reactions typically release energy in the form of heat and light.

Therefore, the only accurate statement regarding the categories of chemical reactions is the one about synthesis reactions.