Boiling does not occur when:
Because in a closed vessel the amount of liquid is constant i.e the water which is converted into vapour again condenses to form water and boiling occurs when vapour pressure is equal to atmospheric pressure since it is closed so they couldn't be equal.
The liquids boil at lower temperature at high altitude because:
At higher altitudes, air pressure is lower. When atmospheric pressure is lower, such as at a higher altitude, it takes less energy to bring water to the boiling point. Less energy means less heat, which means water will boil at a lower temperature at a higher altitude.
The vapour pressure of a liquid depends upon:
Vapor pressure is an intensive property, since it only depends on the fraction of the surface particles that can vaporize.
A liquid enclosed in 1.0L flask at 298K. The vapour pressure exerted by the liquid is 20.0 mm. when the same liquid is enclosed in a flask of 5L capacity at the same temperature, the vapour pressure of the liquid will be:
The vapour pressure of a liquid depends only on the nature of the liquid and the temperature. It does not depend on the volume of the container so it is 20.0mm.
On increasing the temperature of water, the surface tension of water:
Surface Tension is a property of liquid at rest by virtue of which a liquid surface gets contracted to a minimum area and behaves like a stretched membrane.
An increase in temperature of water (or any liquid) leads to an increase in kinetic energy of molecules. Thus, intermolecular forces among molecules are lowered and a decrease in surface tension is noticed.
The phenomenon responsible for spherical shape of liquid drops is:
The cohesive forces between liquid molecules is responsible for the surface tension. The molecules of water on the surface don't have like molecules around it.So the water droplets tend to be pulled into shape of spherical due to cohesive forces.Thats why, the drop of water is always spherical.
The S.I unit of viscosity is:
This is the SI unit of viscosity, equivalent to newton-second per square metre (N. s m-2). It is sometimes referred to as the poiseuille (symbol Pl). One poise is exactly 0.1 Pa
Vapour density of a diatomic elementary gas is 16. The atomic mass of gas is:
Vapour density is equal to molecular mass by 2 therefore the molecular mass of the gas will be 32 so we have a diatomic elementary gas so atomic mass will be molecular mass divided by two of the atomic mass of the gas will be 16.
Greater the viscosity, the:
Viscosity is the measure of resistance of a fluid to flow. A fluid that is highly viscous has a high resistance (like having more friction) and flows slower than a low-viscosity fluid. As Honey would move slower than water, so honey would have a greater viscosity.
Vapour pressure of a liquid decreases with increase in:
The vapor pressure of a liquid is the equilibrium pressure of vapor above the liquid at a given temperature. Thus, all else (molar mass, for example) equal, a polar molecule will generally have a lower vapor pressure than a non-polar molecule.
The magnitude of the surface tension of a liquid depends on:
Surface tension depends on the attractive forces acting b/w molecules.
S = F/l
Dry O2 is:
The amount of water vapor in the air also affects the density. Water vapor is a relatively light gas when compared to diatomic Oxygen and diatomic Nitrogen. Thus, when water vapor increases, the amount of Oxygen and Nitrogen decrease per unit volume and thus density decreases because mass is decreasing.
A student was given Water, Benzene, Orange juice, and Glycerol to pipette out in four different beakers. The liquid that will be relatively difficult to be sucked into the pipette will be:
The reason behind is that it is a viscous liquid.
The mass of 112 ml of N2 at STP on liquefaction is:
Number of moles when condition of STP is given by given volume divided by 22400 this will give number of moles and after that number of moles X molecular mass will give the mass of the given sample.
Viscosity arises due to:
Viscosity is simply the frictional force that arises between adjacent layers of fluid that are in relative motion. Viscosity is a measurement of how resistant a fluid is to attempts to move through it.
Which of the following sets consists of gases with same rate of diffusion:
Graham's law states that the rate of diffusion or effusion of a gas is inversely proportional to the square root of its molar mass. r ∝ 1/√M.
In option A, all the compounds have the same mass(44g).
The property of a liquid that increases with a increase in temperature is:
Vapour pressure is the only property which decreases with increase in temperature. A pure liquid experiences a greater amount of vapour pressure as against a liquid's solution. It is inversely proportional to the forces of attraction existing between the molecules of a liquid. It increases with a rise in the temperature. This is because the molecules gain kinetic energy and thus, vapourise briskly. On the other hand, with increase in kinetic energy of molecules, Viscosity and surface tension decreases.
The S.I unit of Surface tension is:
S = F/l
So the SI unit of surface tension is Nm-1
The vapour pressure of water at 300 K in a closed container is 0.4 atm. If the volume of container is doubled, its vapour pressure at 300 K will be:
Vapour pressure will be the same because it doesn't depend on the volume. It depends only on temperature.
Boiling is condition of:
Boiling is the free vaporisation throughout the liquid. Every molecule of the sample has the same kinetic energy to dissociate from the liquid state. So this will result in free vapourisation.On the other hand, evaporation is restricted vaporisation throughout the liquid. As the molecules present on the surface only vaporises.