Question

Find the heat transferred to the water, when the temperature of a 20-gram sample of water is increased from ${10}^o$C to ${30}^o$C?

• A. 400 calories
• B. 600 calories
• C. 20 calories
• D. 200 calories
• E. 30 calories

Answer 1

Answer: (A)

400 calories

When the temperature of a 20-gram sample of water is increased from 10 deg C to 30 deg C, the heat transferred to the water is obtained by multiplying the mass of water with heat capacity and the temperature change.
The heat capacity of water is 1 cal/g/deg C.
The temperature change is $30-10={20}^{o}C$.
The heat transferred to the water is $20\times 1\times (30-10)=400$ cal.