A 60 g piece of zinc is initially at 20°C. It is then dropped into 200 g of water, which is at 100°C. Assuming no heat loss to the surroundings, what is the final temperature of the system? (The specific heat capacity of zinc is 0.389 J/g°C and the specific heat capacity of water is 4.18 J/g°C.)

• A. 95°C
• B. 90°C
• C. 75°C
• D. 85°C

Answer: (B)

Verified step by step guidance

1. Identify the principle of conservation of energy, which states that the heat lost by the water will be equal to the heat gained by the zinc, assuming no heat loss to the surroundings.
2. Set up the equation for heat transfer: \( q_{\text{zinc}} = -q_{\text{water}} \), where \( q \) represents the heat energy.
3. Use the formula for heat transfer: \( q = m \cdot c \cdot \Delta T \), where \( m \) is mass, \( c \) is specific heat capacity, and \( \Delta T \) is the change in temperature.
4. Substitute the known values into the equation for zinc: \( q_{\text{zinc}} = 60 \text{ g} \cdot 0.389 \text{ J/g°C} \cdot (T_f - 20°C) \).
5. Substitute the known values into the equation for water: \( q_{\text{water}} = 200 \text{ g} \cdot 4.18 \text{ J/g°C} \cdot (100°C - T_f) \).