Question

Curdling of milk is an example of

• A. Slow change
• B. Desirable change
• C. Irreversible change
• D. All of these

Answer 1

The correct option is D

All of these

Explanation for correct options:

Option A

• Curdling of milk is a slow change because it takes some hours to convert into curd.
• The changes that take a long time to take are called slow changes.

Option B

• Curdling of milk is a desirable change, because when we want to eat curd then it is necessary to change milk into curd.
• The changes that are useful to us and want them to take place are called desirable changes.

Option C

• If once milk is changed into curd, we can not change it back to milk.
• Milk is changed into curd due to the formation of lactic acid.
• It is an irreversible process.
• The changes that can not be reversed to obtain a substance back in its original form are called irreversible changes.

Therefore, all the options are correct. Hence, (d) is the correct option.