Question

Water of mass 20 g at $0^{\circ }$C is mixed with 40 g of water at ${10}^{\circ }$C, final temperature of the mixture is

• A. 5°C
• B. 0°C
• C. 20°C
• D. 6.66°C

Answer 1

The correct option is D 6.66°C

Let $\theta$ be the temperature of the mixture.
Heat gained by water at $0^{\circ }$C = Heat lost by water at ${10}^{\circ }$C
c$m_1$($\theta$ - 0) = c$m_2$(10 - $\theta$ )
$\theta$ = $\frac{400}{60}$ = ${6.66}^{\circ }$C