What concentration of nitrogen should be present in a glass of water at room temperature? Assume a temperature of `25^@C`, a total pressure of 1 atmosphere and mole fraction of nitrogen in air of 0.78.
`(K_H for nitrogen=8.42xx10^-17 M/(mm Hg))`

What amount of heat must be supplied to 2.0 xx 10^-2 kg of nitrogen (at room temperature) to raise its temperature by 45 ^@C at constant pressure ? (Molecular mass of N_2 = 28, R = 8.3 J mol^-1 K^-1. )

What concentration of HCOO^(-) is present in a solution of weak of 0.01 M HCOOH (K_(a)=1.8xx10^(-4) and 0.01 M HCl?

The air is a mixture of number of gases. The major components are oxygen and nitrogen with approximate proportion of 20% is to 79% by volume at 298K. The water is in equilibrium with air at a pressure of 10 atm. Henry's law constants for oxygen and nitrogen at 298 K are 3.30xx10^7mm and 6.51xx10^7mm respectively. calculate the composition of these gases in water.

Estimate the total number of air molecules (inclusive of oxygen, nitrogen, water vapour and other constituents) in a room of capacity 25.0 m^3 at a temperature of 27 ^@C and 1 atm pressure.

Two narrow bores of diameters 3.0 mm and 6.0 mm are joined together to form a U-tube open at both ends. If the U-tube contains water, what is the difference in its levels in the two limbs of the tube ? Surface tension of water at the temperature of the experiment is 7.3xx 10^-2 N m^-1 '. Take the angle of contact to be zero and density of water to be 1.0xx 10^3 kg m^- 3 ( g = 9.8 m s^-2 ) .

A brass wire 1.8 m long at 27^@C is held when taut with little tension between two rigid supports. If the wire is cooled to a temperature - 39^@C , what is the tension developed in the wire, if tis diameter is 2.0 mm? Coefficient of linar expansion of brass = 2.0 xx 10^5 ^@C^-1 , Young's modulus of brass = 0.91 xx 10^11 Pa .

A compressed cylinder of gas contains 1.50xx10^(3) g of N_(2) gas at a pressure of 2.0xx10^(7) Pa and a temperature of 17.1^(@)C . What volume of gas has been released into the atmosphere if the final pressure in the cylinder is 1.80xx10^(5) Pa ? Assume ideal behaviour and that the gas temperature is unchanged.

A small bubble rises from the bottom of a lake, where the temperature and pressure are 8^(@)C and 6.0 atm , to the water's surface, where the temperature is 25^(@)C and pressure is 1.0 atm . Calculate the final volume of the bubble if its initial volume was 2mL .