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 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))

Calculate the amount of KCl which must be added to 1 kg of water so that its freezing point is depressed by 2 K.

An oxygen cylinder of volume 30 litres has an initial gauge pressure of 15 atm and a temperature of 27 ^@C . After some oxygen is withdrawn from the cylinder, the gauge pressure drops to 11 atm and its temperature drops to 17 ^@C . Estimate the mass of oxygen taken out of the cylinder ( R= 8.31 J mol^-1 K^-1 ’, molecular mass of O_2 = 32 u)

10g of non-volatile solute when dissolved in 100g of benzene raises its boiling point by 1^@ C. What is the molecular mass of the solute. ( k_b for benzene=2.53 K kg mol^-1 )

Calculate the number of kJ of heat neccesary to raise the temperature of 60.0g of aluminum from 35^(@) C to 55^(@)C . Molar heat capacity of Al is 24 J mol^(-1) k^(-1) .

0.32 g of oxygen is kept in a rigid container and is heated .Find the heat energy needed to raise the temperature from 25^@C to 35^@C .The molar heat capacity of oxygen at constant volume is 20 J mol^(-1) K^(-1) .

The osmotic pressure of 0.2 molar solution of urea at 27^@C (R=0.082 litre atm "mol"^(-1) K^(-1)) is

What is the de-Broglie wavelength of a dust particle of mass 1.0 xx 10^-9 kg drifting with a speed of 2.2 m/s?