How do you calculate the latent heat of vaporization of water?
How do you calculate the latent heat of vaporization of water?
Latent heat calculation The specific latent heat is different for solid to liquid transition and liquid to gas transition. For example, if we want to turn 20 g of ice into water we need Q = 20 g * 334 kJ/kg = 6680 J of energy. To turn the same amount of water into vapor we need Q = 45294 J .
Why latent heat of steam decreases with increase in pressure?
The heat energy (enthalpy of evaporation) needed by the water at higher pressure to change it into steam is actually less than the heat energy required at atmospheric pressure. This is because the specific enthalpy of evaporation decreases as the steam pressure increases.
What is effect of increase of pressure on the enthalpy of steam?
The higher the pressure of a boiler the more heat must be applied to make steam. With the increased pressure, you in turn get steam at higher temperatures. Higher temperature steam contains more energy per pound, which is known as Enthalpy….
What is the effect of Vapour pressure on heat?
The vapor pressure of a liquid varies with its temperature, as the following graph shows for water. The line on the graph shows the boiling temperature for water. As the temperature of a liquid or solid increases its vapor pressure also increases. Conversely, vapor pressure decreases as the temperature decreases.
Does boiling point increase with temperature?
Boiling point of a liquid increases with increase in temperature pressure….
What is the formula of Vapour pressure?
Raoult’s equation shows how to calculate the change in the vapor pressure of a solution from the vapor pressure of the pure solvent: Psolution = xsolventPsolvent, where Psolution is the resulting vapor pressure of the solution, xsolvent is the mole fraction of the solvent and Psolvent is the vapor pressure of the pure …
What does Vapour pressure tell you?
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.
Does vapor pressure depend on volume?
Volume does not affect vapor pressure ! The liquid in a container is in equilibrium with the vapor. Furthermore, if the volume is increased, some of the liquid will change into it’s vapor state….
What happens to vapor pressure as volume increases?
An increase in volume means that less gas particles per unit area are pushing on the surface of the liquid, which means that it is easier for liquid particles to escape into the gaseous phase. As the system stabilizes into equilibrium, the final vapour pressure would be lower than the initial vapour pressure.
Is atmospheric pressure of water dependent on volume?
Vapor pressure is the pressure exerted by a liquid back on the atomosphere. Vapor pressure depends on the nature of the liquid and the temperature. No matter what volume the water is, the vapor pressure of the water is the same as long as the temperature is not change….
Can vapor pressure be greater than 1 atm?
At a pressure greater than 1 atm, water boils at a temperature greater than 100°C because the increased pressure forces vapor molecules above the surface to condense. Hence the molecules must have greater kinetic energy to escape from the surface. Conversely, at pressures less than 1 atm, water boils below 100°C….
Why does water boils when the vapor pressure is equal to atmospheric pressure?
Vapor pressure can be increased by heating a liquid and causing more molecules to enter the atmosphere. At the point where the vapor pressure is equal to the atmospheric pressure boiling will begin. The gas, as bubbles in the liquid, will rise to the surface and be released into the atmosphere….