HSC Science (General) 12th Standard Board Exam - Maharashtra State Board Important Questions for Chemistry

Explain the following term:

Substitutional impurity defect

Explain the following term:

Interstitial impurity defect

Silver crystallizes in the fcc structure. If the edge length of the unit cell is 400 pm, calculate the density of silver (Atomic mass of Ag = 108).

The number of particles present in Face Centred Cubic Unit cell is/are ______.

Predict the type of cubic lattice of a solid element having edge length of 400 pm and density is 6.25 g/ml.
(Atomic mass of element = 60)

Write the formula to determine the molar mass of a solute using freezing point depresssion method.

Why is molality of a solution independent of temperature?

1.0 x10^-3Kg of urea when dissolved in 0.0985 Kg of a solvent, decreases freezing point of the solvent by 0.211 k. 1.6x10 Kg of another non-electrolyte solute when dissolved in 0.086 Kg of the same solvent depresses the freezing point by 0.34 K. Calculate the molar mass of the another solute. (Given molar mass of urea = 60)

The substance ‘X’, when dissolved in solvent water gave molar mass corresponding to the molecular formula ‘X3’. The van’t Hoff factor (i) is _______.

(A) 3

(B) 0.33

(C) 1.3

(D) 1

The boiling point of water at high altitude is low. because________________ .

(a) the temperature is low.                                         

(b) the atmospheric pressure is low.

(c) the temperature is high.

(d) the atmospheric pressure is high

Define Cryoscopic constant.

Determine the osmotic pressure of a solution prepared by dissolving 2.5 × 10⁻² g of K₂SO₄ in 2L of water at 25°C, assuming that it is completely dissociated.

(R = 0.0821 L atm K⁻¹ mol⁻¹, Molar mass of K₂SO₄ = 174 g mol⁻¹)

Determine the osmotic pressure of a solution prepared by dissolving 2.5 × 10⁻² g of K₂SO₄ in 2L of water at 25°C, assuming that it is completely dissociated.

(R = 0.0821 L atm K⁻¹ mol⁻¹, Molar mass of K₂SO₄ = 174 g mol⁻¹)

Which of the following solutions shows maximum depression in freezing point?

(A) 0.5 M Li₂SQ₄

(B) 1 M NaCl

(C) 0.5 M A1₂(SO₄)₃

(D) 0.5 MBaC1₂

Explain, why do aquatic animals prefer to stay at lower level of water during summer?

Which of the following is not a colligative property?

Which of the following is not a colligative property?

Gas (A) is more soluble in water than Gas (B) at the same temperature. Which one of the two gases will have the higher value of KH (Henry’s constant) and why

Why do gases always tend to be less soluble in liquids as the temperature is raised?

Calculate the amount of CaCl₂ (molar mass = 111 g mol⁻¹) which must be added to 500 g of water to lower its freezing point by 2 K, assuming CaCl₂ is completely dissociated. (K_f for water = 1.86 K kg mol⁻¹)