Chemistry Question Bank

The vapour pressure of a solvent decreases by 10 mm of Hg when a non-volatile solute was added to the solvent. The mole fraction of the solute in the solution is 0.2. What should be the mole fraction of the solvent if…

At a particular temperature, the vapour pressures of two liquids A and B are respectively 120 and 180 mm of Hg respectively. If 2 moles of A and 3 moles of B are mixed to form an ideal solution, the vapour pressure of…

Assertion: Lowering of vapour pressure is directly proportional to osmotic pressure of the solution. Reason: Osmotic pressure is a colligative property.

Assertion: If one component of a solution obeys Raoult’s law over a certain range of composition, the other component will not obey Henry’s law in that range. Reason: Raoult’s law is a special case of Henry’s law.

Which observation(s) reflect(s) colligative properties? (i) A 0.5 m NaBr solution has a higher vapour pressure than a 0.5 m BaCl₂ solution at the same temperature (ii) Pure water freezes at the higher temperature than…

Assertion: If a liquid solute more volatile than the solvent is added to the solvent, the vapour pressure of the solution may increase. Reason: In the presence of a more volatile liquid solute, only the solute will fo…

Assertion: The water pouch of instant cold pack for treating athletic injuries breaks when squeezed and NH₄NO₃ dissolves lowering the temperature. Reason: Addition of non-volatile solute into solvent results into depr…

Which of the following 0.10 m aqueous solutions will have the lowest freezing point?

An aqueous solution of NaCl freezes at –0.186 °C. Given that 0.512 H O b K K kg mol and 1.86 H O f K K kg mol , the elevation in boiling point of this solution is

Assertion: If red blood cells were removed from the body and placed in pure water, pressure inside the cells increases. Reason: The concentration of salt content in the cells increases.

The freezing point of equimolal aqueous solution will be highest for

b b o cal C kg mol gm K K x x x

Sodium metal crystallizes in a body centred cubic lattice with a unit cell edge of 4.29 Å. The radius of sodium atom is approximately:

Density of NaCl crystal by not considering the unoccupied sites but only the occupied sites = 2.165 × 103 kg m–3. The percentage of unoccupied sites in NaCl crystal is

A compound contains two types of atoms X and Y. It crystallises in a cubic lattice with atoms X at the corners of the unit cell and atoms Y at the body centre. The simplest possible formula of this compound is

Ag crystallises as fcc. If radius of Ag is 144 pm then its density will be (a)₁₀ g cm–3

A metallic element has a cubic lattice. Each edge of the unit cell is 2 Å. The density of the metal is 2.5 g cm–3 . The unit cells in 200 g of the metal are

In a solid ‘AB’ having the NaCl structure, ‘A’ atoms occupy the corners and face centres of the cubic unit cell but all the face-centred atoms along one of the axes are removed and ‘B’ atoms occupy octahedral voids, t…

Total volume of atoms present in a face centred cubic unit cell of a metal is (r = radius of atom) (a) r (b) r (c) r (d) r

Edge length of a cube is 400 pm, its body diagonal would be

In a compound, atoms of element Y form ccp lattice and those of element X occupy 2/3rd of tetrahedral voids. The formula of the compound will be

Example of unit cell with crystallographic dimensions , 90º, 90º a b c is

Number of unit cells in 4 g of X (atomic mass=40). Which crystallises in bcc pattern is (NA=Avogadro number)

The unit cell of a binary alloy composed of A and B metals, has ccp. Structure with A atoms occupying the corners and B atoms occupying centres of each face of the cube. If during the crystallisation of this alloy, in…

In a face centred cubic lattice, atom A occupies the corner positions and atom B occupies the face centre positions. If one atom of B is missing from one of the face centred points, the formula of the compound is