Answer:
4.5 °C
Explanation:
According to the law of conservation of energy, the sum of the heat lost by the iron and the heat gained by the water is zero.
Qi + Qw = 0
Qi = -Qw [1]
We can calculate each heat using the following expression.
Q = c × m × ΔT [2]
where,
- c: specific heat capacity
- ΔT: change in the temperature
Replacing [2] in [1], we get
ci × mi × ΔTi = -cw × mw × ΔTw
ΔTw = -ci × mi × ΔTi / cw × mw
ΔTw = -0.108 cal/g.°C × 700 g × (-30 °C) / 1 cal/g.°C × 500 g
ΔTw = 4.5 °C
