Question

question 1
1 pts
when the rate of vaporization and the rate of condensation are in equilibrium,...
there is no gas present.
there are equal amounts of liquid and gas.
the vapor pressure will be stable.
the liquid will boil.

Explanation:

1. Analyze "there is no gas present": Vaporization produces gas, condensation consumes gas. At equilibrium, gas is present (since vaporization occurs), so this is wrong.
2. Analyze "there are equal amounts of liquid and gas": Equilibrium between vaporization (liquid to gas) and condensation (gas to liquid) doesn't imply equal amounts of liquid and gas. The amounts depend on conditions, so this is wrong.
3. Analyze "the vapor pressure will be stable": Vapor pressure is the pressure of the gas above the liquid. When vaporization rate (liquid → gas) equals condensation rate (gas → liquid), the amount of gas above the liquid stays constant, so vapor pressure (which depends on gas amount/partial pressure) becomes stable. This matches the concept of dynamic equilibrium in phase changes.
4. Analyze "the liquid will boil": Boiling occurs when vapor pressure equals atmospheric pressure, which is a different condition than vapor - condensation equilibrium (which is about the balance between the two phase - change rates at a given temperature, not related to atmospheric pressure in this direct way). So this is wrong.

Answer:

C. the vapor pressure will be stable.