HSC Science (General) १२ वीं कक्षा - Maharashtra State Board Important Questions for Chemistry

Which stoichiometric defect decreases the density of the crystal?

Explain ionic solids are hard and brittle.

Explain ionic solids are hard and brittle.

An ionic compound crystallises in FCC type structure with ‘A’ ions at the centre of each face and ‘B’ ions occupying corners of the cube. The formula of compound is _______.

An ionic compound crystallises in FCC type structure with ‘A’ ions at the centre of each face and ‘B’ ions occupying corners of the cube. The formula of compound is _______.

An ionic crystal lattice has limiting value of radius ratio as 0.414 to 0.732; the co-ordination number of its cation is _______.

(A) 6

(B) 4

(C) 3

(D) 12

Classify the following solids into different types:

a. Ammonium phosphate

b. Brass

c. S₈ molecule

d. Diamond

Classify the following solids into different types:

a. Ammonium phosphate

b. Brass

c. S₈ molecule

d. Diamond

A metal crystallises into two cubic faces namely face centered (FCC) and body centered (BCC), whose unit cell edge lengths are 3.5 Å and 3.0 Å respectively. Find the ratio of the densities of FCC and BCC.

Explain with reason sign conventions of ΔS in the following reaction

N_2(g) + 3H_2(g) → 2NH_3(g)

Explain with reason sign conventions of ΔS in the following reaction

CO_2(g) → CO_2(g)

Schottky defects are observed in which solid among the following?

(a) Brass

(b) Cesium Chloride

(c) Zinc sulphide

(d) Stainless steel

A face centred cube (FCC) consists of how many atoms? Explain

Which of the following parameters are correct for triclinic lattice?

(A) α = β = γ = 90° and a = b = c

(B) α ≠ β ≠ γ = 90° and a ≠ b ≠ c

(C) α = γ = 90°, β ≠ 90° and a ≠ b ≠ c

(D) α ≠ β ≠ γ ≠ 90° and a ≠ b ≠ c

Calculate the number of atoms present in 2 gram of crystal which has face-centred cubic
(FCC) crystal lattice having edge length of 100 pm and density 10 gcm−3

What are Frenkel defect

A pure semiconductor is ________.

(a) an extrinsic semiconductor

(b) an intrinsic semiconductor

(c) p-type semiconductor

(d) n-type semiconductor

An ionic crystal lattice has `r^+/r` radius ratio of 0.320, its coordination number is __

(a) 3

(b) 4

(c) 6

(d) 8

The density of iron crystal is 8.54-gram cm^–3. If the edge length of the unit cell is 2.8 A° and atomic mass is 56 gram mol^–1, find the number of atoms in the unit cell.  (Given: Avogadro's number = 6.022x10²³,1A° = 1x10^-8 cm)

Distinguish between p-type and n-type semiconductors.