Question
UPSC Prelims 2014 Question:
Which of the following is/are the example/examples of chemical change?
- Crystallization of sodium chloride
- Melting of ice
- Souring of milk
Select the correct answer using the code given below:
Answer (Detailed Solution Below)
Option 2: 3 only
Detailed Solution
Explanation:
- A chemical change is a process in which one or more substances are altered into one or more new and different substances. In other words, a chemical change is a chemical reaction involving the rearrangement of atoms.
- While a physical change can often be reversed, a chemical change typically cannot be, except through more chemical reactions. Crystallization of sodium chloride and melting of ice can be reversed, hence these are physical changes. So, point 1 and 2 are not correct.
- Souring of milk involves change of atoms, and typically cannot be reversed. Which is why it's a chemical change. So, point 3 is correct.
Therefore, option (2) is the correct answer.
Subject: Science & Technology | Chemistry
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