CBSE 12th 2026 Solutions Important Questions for Exam Day

 Calculate the molarity of the solution containing 5 g of NaOH in 450 ML solution.

If N2 gas is bubbled through water at 293K, how many millimoles of N2 gas would dissolve in 1L of water? Assume that N2 exerts a partial pressure of 0.987 bar. Given that Henry's law constant for N2 at 293K is 76.48 kbar.

18 g of glucose C6H12O6 is dissolved in 1 kg of water in a saucepan. At what temperature will water boil at 1.013 bar? Kb for water is 0.52 K kg mol-1.

2g of benzoic acid (C6H5COOH) dissolved in 25g of benzene shows a depression in freezing point equal to 1.62K. Molal depression constant for benzene is 4.9kg m−1. What is the percentage association of acid if it forms a dimer in solution?

Concentrated nitric acid used in laboratory work is 68% nitric acid by mass in aqueous solution. What should be the molarity of such a sample of the acid if the density of the solution is 1.504 g mL–1?

Calculate the mass of a non-volatile solute (molar mass 40 g mol–1), which should be dissolved in 114 g octane to reduce its vapour pressure to 80%.

Vapour pressure of water at 293 K is 17.535 mm Hg. Calculate the vapour pressure of water at 293 K when 25 g of glucose is dissolved in 450 g of water.

Benzene and toluene form an ideal solution over the entire range of composition. The vapour pressure of pure benzene and toluene at 300 K is 50.71 mm Hg and 32.06 mm Hg respectively. Calculate the mole fraction of benzene in the vapour phase if 80 g of benzene is mixed with 100 g of toluene.

Determine the osmotic pressure of a solution prepared by dissolving 25mg of K2SO4 in 2 litres of water at 25 degrees c. Assuming that it is completely dissociated.