The water in Glass B is warmer than
in Glass A. How can you tell? The water in Glass B is
evaporating more rapidly than in Glass A (2 arrows in B versus 1 arrow
in A).
There is more water vapor in Glass A than in Glass B. Water vapor is condensing more rapidly in Glass A than in Glass B. The rate of condensation depends on how much water vapor is in the air. There must be more water vapor in the air in Glass A in order to provide the higher rate of condensation.
The relative humidity in Glass A is more than 100% (the air is supersaturated). Because the rate of condensation in Glass A is greater than the rate of evaporation, the rate of condensation in Glass A will decrease. It will continue to decrease until it is equal to the rate of evaporation.
The relative humidity in Glass B is less than 100% (the air is subsaturated). There is more evaporation than condensation. The amount of water vapor in Glass B will increase until there is enough water vapor to provide 2 arrows of condensation which will balance the rate of evaporation.
This is what the two glasses will look like once they've achieved
equilibrium. The air in both glasses is now saturated and the RH
= 100%. The air in Glass B, the warmer glass, contains more water
vapor.
There is more water vapor in Glass A than in Glass B. Water vapor is condensing more rapidly in Glass A than in Glass B. The rate of condensation depends on how much water vapor is in the air. There must be more water vapor in the air in Glass A in order to provide the higher rate of condensation.
The relative humidity in Glass A is more than 100% (the air is supersaturated). Because the rate of condensation in Glass A is greater than the rate of evaporation, the rate of condensation in Glass A will decrease. It will continue to decrease until it is equal to the rate of evaporation.
The relative humidity in Glass B is less than 100% (the air is subsaturated). There is more evaporation than condensation. The amount of water vapor in Glass B will increase until there is enough water vapor to provide 2 arrows of condensation which will balance the rate of evaporation.