Question

Assertion: It one gram of ice is mixed with 1 g of water at
, then the final temperature of mixture is zero. Reason: Latent heat of ice is 80 cal/g.

• A. If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
• B. If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
• C. If Assertion is true but Reason is false.
• D. If both Assertion and Reason are false.

Answer 1

Answer: (B)

Heat required by ice to melt $ =1\times 80=80\text{ cal} $ Heat lost by water is cooling from $ \text{80}{{\,}^{\text{o}}}\text{C} $ to $ \text{0}{{\,}^{\text{o}}}\text{C}\text{.} $ $ =1\times 1\times (80=0) $ $ =80\,\text{cal} $ From principle of colorimetry heat lost = Heat gained. Thus, the final temperature of the mixture will be $ \text{0}{{\,}^{\text{o}}}\text{C}\text{.} $