試題詳解

53. Salt A and salt B were dissolved separately in 100 mL beakers of water. The water temperatures were measured and recorded as shown in the table below:
Salt A: initial water temp. 25.1°C final water temp. 30.2°C
Salt B: initial water temp. 25.1°C final water temp. 20.0°C
Which statement is a CORRECT interpretation of these data?
(A) The dissolving of only salt A was endothermic.
(B) The dissolving of only salt B was exothermic.
(C) The dissolving of both salt A and salt B was endothermic.
(D) The dissolving of salt A was exothermic and the dissolving of salt B was endothermic.
(E) The dissolving of both salt A and salt B was endothermic.