How many moles of oxygen are present in `400 cm^3` sample of a gas at a pressure of 760 mm Hg at a temperature of `27^@C`?

How many moles of oxygen present in 1000gms of CaCO_3 ?

How many moles of oxygen are given by the complete decomposition of 1.225 g KClO_3 ?

A very dilute saturated aqueous solution of a sparingly soluble salt X_3 Y_4, has a vapour pressure of 20 mm Hg at temperature T, while pure water exerts a pressure of 20.0126 mm Hg at the same temperature. Calculate molality (m) at temperature T:

How many moles of Th (NO_3)_4 should be dissolved in 15 moles of water so that vapour pressure of water is reduced by 40%: a)1 b)2 c)3 d)4

Calculate the number of moles of hydrogen present in 10 dm^(3) of the gas at 25^(@)C and 1.5 atm pressure.

NH_3 , gas at STP is kept in a cylinder of volume 5600mL. a) How many moles of NH_3 , is present in the cylinder? b) Calculate the mass of gas in the cyclinder. c) Find the number of molecules in the gas calculate the number of atoms in it. (Hint: Atomic mass, N=14, H-D)

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 atmospheric pressure.

A gas occupy 400 ml volume at 47^@C and 800 mm of Hg pressure. What will be its pressure at a height where the temperature is 27^@C and volume of the gas is 450 ml?

At 25^@C and 760 mm of Hg pressure a gas occupies 600mL volume. What will be its pressure at a height where temperature is 10^@C and volume of the gas is 640 mL?