AIPMT-PRELIMS Chemistry Solutions Class 12 Questions

Pₐ and P_b are the vapour pressures of pure liquid components A and B, respectively of an ideal binary solution. If xₐ represents the mole fraction of component A, the total pressure of the solution will be

Buffer solutions have constant acidity and alkalinity because:

Mole fraction of the solute in a 1.00 molal aqueous solution is

The van't Hoff factor i for a compound which undergoes dissociation in one solvent and association in other solvent is respectively

The freezing point depression constant for water is –1.86°Cm⁻¹. If 5.00 g Na₂SO₄ is dissolved in 45.0 g H₂O, the freezing point is changed by –3.82°C. Calculate the van't Hoff factor for Na₂SO₄.

25.3 g of sodium carbonate, Na₂CO₃ is dissolved in enough water to make 250 mL of solution. If sodium carbonate dissociates completely, molar concentration of sodium ion, Na⁺ and carbonate ions, CO₃²⁻ are respectively (Molar mass of Na₂CO₃ = 106 g mol⁻¹)

An aqueous solution is 1.00 molal in KI. Which change will cause the vapour pressure of the solution to increase?

A solution of sucrose (molar mass = 342 g mol⁻¹) has been prepared by dissolving 68.5 g of sucrose in 1000 g of water. The freezing point of the solution obtained will be (Kf for water = 1.86 K kg mol⁻¹)

A 0.0020 m aqueous solution of an ionic compound Co(NH₃)₅(NO₂)Cl freezes at −0.00732 °C. Number of moles of ions which 1 mol of ionic compound produces on being dissolved in water will be (kₓ = −1.86°C/m)

Concentrated aqueous sulphuric acid is 98% H₂SO₄ by mass and has a density of 1.80 g mL⁻¹. Volume of acid required to make one litre of 0.1M H₂SO₄ solution is

0.5 molal aqueous solution of a weak acid (HX) is 20% ionised. If Kf for water is 1.86 K kg mol⁻¹, the lowering in freezing point of the solution is

In a coal fired power plant electrostatic precipitators are installed to control emission of

A solution containing 10g per dm³ of urea (molecular mass = 60g mol⁻¹) is isotonic with a 5% solution of a non-volatile solute. The molecular mass of this non-volatile solute is:

1.00 g of a non-electrolyte solute (molar mass 250 g mol⁻¹) was dissolved in 51.2 g of benzene. If the freezing point depression constant, Kf of benzene is 5.12 K kg mol⁻¹, the freezing point of benzene will be lowered by:

A solution of acetone in ethanol:

During osmosis, flow of water through a semi-permeable membrane is :

The correct order of the mobility of the alkali metal ions in aqueous solution is :

The vapour pressure of two liquids P and Q are 80 and 60 torr, respectively. The total vapour pressure of solution obtained by mixing 3 moles of P and 2 moles of Q would be:

A solution of urea (mol. mass 56 g mol⁻¹) boils at 100.18°C at the atmospheric pressure. If kf and kb for water are 1.86 and 0.512 K kg mol⁻¹ respectively, the above solution will freeze at:

A solution has a 1 : 4 mole ratio of pentane to hexane. The vapour pressure of the pure hydrocarbons at 20°C are 440 mm of Hg for pentane and 120 mm of Hg for hexane. The mole fraction of pentane in the vapour phase would be:

The mole fraction of the solute in one molal aqueous solution is:

Camphor is often used in molecular mass determination because :-

Formation of a solution from two components can be considered as: (i) Pure solvent \( \rightarrow \) separated solvent molecules, \( \Delta H_1 \) (ii) Pure solvent \( \rightarrow \) separated solvent molecules, \( \Delta H_2 \) (iii) Separated solvent and solute molecules \( \rightarrow \) solution, \( \Delta H_3 \) Solution so formed will be ideal if:

Fluoride pollutions mainly affects :-

1 M and 2.5 litre NaOH solution mixed with another 0.5 M and 3 litre NaOH solution. Then find out molarity of resultant solution :-

A solution contains non volatile solute of molecular mass M₂. Which of the following can be used to calculate the molecular mass of solute in terms of osmotic pressure :-

A solution containing components A and B follows Raoult's law :-

Molarity of liquid HCl if density of liq. HCl is 1.17 gm/cc : -

Pure water can be obtain from sea water by

From the colligative properties of solution which one is the best method for the determination of mol. wt of proteins & polymers :