Question

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

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

Answer 1

The correct option is B ${20}^{\circ }C$

Let the final temperature be $T$

$5\times 80+5\times 1\times (T-0)=20\times (45-T)\times 1\Rightarrow 400+5T=900-20T\Rightarrow 20T+5T=900-400\Rightarrow T=20℃$