19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
12g of urea is dissolved in 1 litre of water and 68.4 g of sucrose is dissolved in 1 litre of water. The lowering of vapour pressure of first case is
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: The molecular weight of acetic acid determined by depression in freezing point method in benzene and water was found to be different. Reason: Water is polar, and benzene is nonpolar.
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 of the following 0.10 m aqueous solutions will have the lowest freezing point?
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…
The freezing point of equimolal aqueous solution will be highest for
An aqueous solution of NaCl shows the depression of freezing point of water equal to 0.372 K. The boiling point of BaCl₂ solution of same molality will be [Kf (H₂O)= 1.86 K kg mol–1; Kb(H₂O) = 0.52 K kg mol–1]
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…
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
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…
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