Complete Question:
If heat is added to ice and liquid water in a closed container and after the addition of the heat, ice and liquid water remain, (A) the vapor pressure of the water will decrease. (B) the temperature will increase somewhat. (C) the temperature will decrease somewhat. (D) the vapor pressure of the water will remain constant.
Answer:
A
Step-by-step explanation:
When heat is added to a system, the internal energy of the molecules increases, and they become more agitated, because of that the temperature intends to increase. But when exists a liquid-vapor equilibrium this increase of temperature may be balanced by the vapor pressure.
The vapor pressure is the pressure that the vapor does when it is in equilibrium with the liquid. So, as higher is it, as easy it will be to the liquid to evaporate. When the temperature increases more liquid will evaporate, because the molecules are more agitated, and so the vapor pressure must increase.
But, if the ice and liquid remain, it indicates that no liquid was evaporated, so, the pressure decreased, to avoid the effect of the temperature, which will remain constant.