In a constant-pressure calorimetry experiment, butane was burnt causing a temperature change of 25.5 K in 1200 g of water (specific heat capacity = 4.18 J/g⋅K). Calculate the heat change of the water. Give the answer to three significant figures.

• A. 128,000 J
• B. 127,000 J
• C. 125,000 J
• D. 126,000 J

Answer: (B)

Verified step by step guidance

1. Identify the formula to calculate the heat change: \( q = m \cdot c \cdot \Delta T \), where \( q \) is the heat change, \( m \) is the mass of the substance, \( c \) is the specific heat capacity, and \( \Delta T \) is the change in temperature.
2. Substitute the given values into the formula: \( m = 1200 \text{ g} \), \( c = 4.18 \text{ J/g⋅K} \), and \( \Delta T = 25.5 \text{ K} \).
3. Calculate the product of the mass and the specific heat capacity: \( 1200 \text{ g} \times 4.18 \text{ J/g⋅K} \).
4. Multiply the result from the previous step by the temperature change \( 25.5 \text{ K} \) to find the heat change \( q \).
5. Ensure the final answer is expressed to three significant figures, as required by the problem.