In a calorimetry experiment, if 418 J are recorded for a measurement rather than the correct value, which option shows the correct heat transfer for a 100 g water sample warming by 2°C?

• A. 418 J
• B. 2 J
• C. 8360 J
• D. 836 J

Answer: (D)

Heat transferred to raise the temperature of water depends on the mass, the specific heat capacity of water, and the temperature change, via q = m c ΔT. For 100 g of water with a specific heat of about 4.18 J/g°C and a rise of 2°C, the heat required is 100 × 4.18 × 2 = 836 J. So the correct heat transfer is 836 J. The value 418 J would correspond to a 1°C rise (for the same mass), while 2 J is far too small to heat that much water, and 8360 J would correspond to a 20°C rise.