A student dissolves 5.0 g of an unknown salt in 100 mL of water

CHEMISTRY · Single correct · A Level · Chemistry · Energetics · Energetics

Problem

A student dissolves 5.0 g of an unknown salt in 100 mL of water. The temperature of the water increases from

22.0^{\circ}\text{C}

27.5^{\circ}\text{C}

. Based on this observation, which statement correctly characterizes the process, taking the dissolving salt and water together as the system? (a) The process is endothermic and

q_{\text{system}}>0

. (b) The process is exothermic and

q_{\text{system}}<0

. (c) The process is exothermic and

q_{\text{system}}>0

. (d) The sign of

q_{\text{system}}

cannot be determined without the heat capacity of the solution.

Related theory

Thermodynamics
First law of thermodynamics
Endothermic and exothermic reactions

Browse the problem library