Question

5 g of ice at $0^0$ C and 20 g of water at ${45}^0$ C are mixed. The temperature of the mixture will be

• A. ${10}^0$ C
• B. ${20}^0$ C
• C. ${30}^0$ C
• D. ${40}^0$ C

Answer 1

The correct option is B ${20}^0$ C

Let the final temperature be $T$

$5\times 80+5\times 1(T-0)=20\times 1\times (45-T)\Rightarrow 400+5T=900-20T\Rightarrow 25T=900-400\Rightarrow T=\frac{500}{25}=20℃$