Question

Which of the following statements holds true for a chemical change?

A. In a chemical change, no new substance is formed
B. In a chemical change, a substance changes its phase
C. In a chemical change, the molecular structure of a substance changes
D. In a chemical change, one substance dissolves into another

Answer 1

c. in a chemical change the molecular structure changes.

Answer 2

Answer : The correct option is C.

Explanation :

Chemical change : It is defined as a change in which a new compounds are formed by the chemical reaction. Changes occurs in their chemical composition and properties.

The molecular structure of a substance changes in a chemical reaction is a chemical change.

• Change in molecular structure means that there is a breaking and formation of bonds in a molecule.

The example of chemical change in terms of change in molecular structure is the reaction of hydrogen with oxygen.

The reaction of hydrogen with oxygen is,

`H_2(g)+O_2(g)\rightarrow 2H_2O(l)`

In this reaction, the H-H bond is break and O-H bond is form.