GK QUESTION#3358
Consider the following statements:
1. A physical change is generally reversible and no new substance is formed.
2. A chemical change results in the formation of a new substance with different properties.
3. Curdling of milk is a physical change because it can be reversed by cooling.
Which of the above statements are correct?
Show Answer
Answer
A. 1 and 2 only
Show Explanation
Explanation
A physical change changes properties such as state or shape without creating a new substance; many such changes are reversible, although not all are. Chemical changes produce new substances. In bacterial curd formation, milk becomes more acidic and proteins coagulate; cooling does not convert curd back to fresh milk. Statements 1 and 2 are correct.