Chemistry - Thermochemistry Question with Solution | TestHub
Two bars of different metals are heated to 60°C and then immersed in identical, insulated containers each containing 200 g of water at 20°C. Will the metal with higher or lower atomic mass cause a greater temperature rise in water?
Options:
Answer:
Solution:
According to the Dulong-Petit law, the molar heat capacity of metals is approximately constant, around 25 J/mol · K. Therefore, the specific heat capacity (s) can be calculated as s = 25/atomic mass. This implies that a lighter metal (one with a lower atomic mass) will have a larger specific heat capacity.
When bars of equal mass (m) are considered, the heat transferred to water (Q) is given by the formula Q = msΔ T, where Δ T is the change in temperature. A metal with a larger specific heat capacity (s) will transfer more heat to the water, resulting in a greater temperature rise. Consequently, the metal with the lower atomic mass will cause the greater temperature increase in the water. This corresponds to option (a).
