Question

A kilogram of aluminum metal and a kilogram of water are each warmed to 75 °C and placed in two identical insulated containers. One hour later, the two containers are opened and the temperature of each substance is measured. The aluminum has cooled to 35 °C, while the water has cooled only to 66 °C. Explain this difference.

Answer 1

The water cooled less than the aluminum after one hour because water has a higher specific heat capacity, meaning it can absorb more heat before increasing in temperature.

Step-by-step explanation:

The difference in the temperatures of the aluminum and water after one hour is due to the specific heat capacity of each substance. Specific heat capacity is the amount of heat required to raise the temperature of one kilogram of a substance by one degree Celsius. Water has a high specific heat capacity of 4.18 J/g°C, which is much higher than that of aluminum, which is about 0.897 J/g°C. This means water can absorb more heat before its temperature rises compared to aluminum.

Therefore, when both substances begin at the same temperature and are allowed to cool, the water will not lose as much temperature as the aluminum for the same period since it stores more heat. This is why after an hour, the aluminum cooled down to 35°C while the water only cooled to 66°C; the water retained more of the stored heat.