The vapour pressure of a given liquid will increase if

Options

A. Temperature is increased
B. Surface area of liquid is increased
C. Volume of liquid in the container is increased
D. Volume of the vapour phase is decreased

Answer

To solve the question regarding the conditions under which the vapor pressure of a given liquid will increase, we need to analyze the options provided and understand the concept of vapor pressure.

### Step-by-Step Solution:

1. **Understanding Vapor Pressure**:
- Vapor pressure is the pressure exerted by the vapor of a liquid when it is in equilibrium with its liquid phase. This means that the rate of evaporation of the liquid equals the rate of condensation of the vapor.

2. **Analyzing the Options**:
- **Option 1: Temperature is increased**:
- When the temperature of a liquid increases, the kinetic energy of the molecules also increases. This leads to more molecules escaping from the liquid phase to the vapor phase, thereby increasing the vapor pressure.
- **Option 2: Surface area of liquid is increased**:
- Increasing the surface area allows more molecules to escape into the vapor phase, but it does not affect the vapor pressure directly. The vapor pressure is a property of the liquid at a given temperature and is not dependent on surface area.
- **Option 3: Volume of liquid in container is increased**:
- Increasing the volume of the liquid does not affect the vapor pressure. Vapor pressure is determined by the temperature and the nature of the liquid, not by the amount of liquid present.
- **Option 4: Phase is decreased**:
- This option is unclear, but if it refers to reducing the amount of liquid (i.e., decreasing the phase of the liquid), it would not increase vapor pressure. Vapor pressure is a characteristic of the liquid at a specific temperature.

3. **Conclusion**:
- The only option that directly leads to an increase in vapor pressure is **Option 1: Temperature is increased**. As the temperature rises, the vapor pressure of the liquid also increases.

### Final Answer:
The vapor pressure of a given liquid will increase if **temperature is increased**.