How does barometric pressure affect vapor pressure?

An increase in atmospheric pressure raises the boiling point of a liquid by raising the vapor pressure of the water above the liquid. This increases the amount of thermal energy needed to increase the vapor pressure of the water to match, raising the boiling point.

Why is it necessary to subtract the vapor pressure of water from the barometric pressure?

This is because, as you are collecting that gas over the water, the water itself will be evaporating untill the pressure of water equals the vapour pressure at that temperature. So, you subtract out the pressure due to the water (the vapour pressure) to determine the pressure of the rest of the gas.

What happens if vapour pressure is low?

Vapour pressure is a measure of the ability of a compound to bond with itself; compound molecules that bond well with each other will have a low vapour pressure (less tendency to escape to the vapour phase), while poorly bonding compounds will have a high vapour pressure.

Why is mercury a convenient fluid to use in a barometer?

Mercury is commonly used in barometers because its high density means the height of the column can be a reasonable size to measure atmospheric pressure. This is because mercury is 13.6 times more dense than water.

Is barometric pressure the same as vapor pressure?

At the normal boiling point of a liquid, the vapor pressure is equal to the standard atmospheric pressure defined as 1 atmosphere, 760 Torr, 101.325 kPa, or 14.69595 psi. The vapor pressure of a liquid at its boiling point equals the pressure of its surrounding environment.

Is vapor pressure a function of pressure?

The pressure exerted by the gas in equilibrium with a solid or liquid in a closed container at a given temperature is called the vapor pressure.

Why is it necessary to correct for the water vapor?

This value is known as the ‘vapou pressure of water’. This means that you must correct the pressure, by subtracting the vapour pressure of water from the measured value to get the actual pressure of the produced gas.

Why is it logical to expect that the vapor pressure of water would increase as the temperature increases?

Why is it logical to expect that the vapor pressure of water would increase as the temperature increases? As the temperature increases, water is more likely to evaporate and the evaporated molecules move faster, colliding with more force (or pressure).

What is meant by vapour pressure of a fluid?

Vapour pressure is a measure of the tendency of a material to change into the gaseous or vapour state, and it increases with temperature. The temperature at which the vapour pressure at the surface of a liquid becomes equal to the pressure exerted by the surroundings is called the boiling point of the liquid.

What is the vapour pressure of mercury?

The vapour pressure of mercury has been determined ebulliometrically over the range 0.05 to 800 kPa (380 to 770 K): above 3 kPa (480 K) by the comparative method with water as the standard, and below 5 kPa by direct measurement of the pressure with a mercury manometer.

What factors affect vapour pressure?

Three common factors that influence vapor press are surface area, intermolecular forces and temperature. The vapor pressure of a molecule differs at different temperatures.