Maharashtra HSC Chemistry Answer Key 2025 (20 Feb) - Download All Sets PDF

(i). Schottky defect is NOT observed in

(d) NiO

(ii). The freezing point of 0.1m aqueous solution of urea, if Kf for water is 1.86 K kg mol−1^is:

d) -0.186°C

(iii). Ozone layer is depleted by

a) NO

(iv). When excess of AgNO₃ is added to a complex, one mole of AgCl is precipitated. The formula of the complex is

a) [CoCl₂ (NH₃)₄]Cl

(v). The value of Δng for the oxidation of 4 moles of sulphur dioxide to sulphur trioxide is:

a) -2

(vi) One-dimensional nanostructure amongst the following is:

d) Nanorods

(vii). Which formula co-relates degree of dissociation and concentration of electrolyte

B) α = √(Ka/b)

(viii). The highest acidic compound among the following is

c)

(ix). The formula used to calculate molar conductivity of an electrolyte is:

c) 1000k / c

(x). Which of the following is a secondary amine?

c) Diphenylamine

Sub Question Number

Answers

(i). Write the structural formula of N, N-dimethylethanamine.

CH3-CH2-N(CH3)2

(ii). Write the reagents used for the reduction of carbonyl group in Clemmensen’s reduction.

The reagents used in Clemmensen reduction are:

• Zinc amalgam (Zn(Hg))
• Concentrated hydrochloric acid (HCl)

Zn-Hg and HCl

(iii). Write the IUPAC name of isoprene.

The IUPAC name of isoprene is 2-methyl-1,3-butadiene

(iv). The rate law equation for A → Product is rate = k[A]ˣ. What is the effect of an increase in the concentration of ‘A’ on the rate of reaction, if x < 0?

Decrease in concentration of ‘A’ increases the rate

(v). What is the molality of an aqueous solution of KBr having freezing point –3.72°C? (Kf for water is 1.86 K kg mol⁻¹)

2 mol/kg

(vi). Write the balanced chemical equation, when excess of ammonia is treated with chlorine

8NH3+3Cl2→6NH4Cl+N28NH_3 + 3Cl_2 → 6NH_4Cl + N_28NH3+3Cl2→6NH4Cl+N2

(vii). Write the number of donor atoms present in EDTA, during the formation of a complex.

6 donor atoms (4 Oxygen, 2 Nitrogen)

(viii). Write the names of the metal elements in brass alloy.

Copper (Cu) and Zinc (Zn)

Section

Question Type

Number of Questions

Questions That Need to be Attempted

Marks per Question

A

MCQs and very short answer-type questions

2 questions with 18 subparts

18

1 x 18 = 18

B

Short answer-type questions

12

8

2 x 8 = 16

C

Short answer-type questions

12

8

3 x 8 = 24

D

Long answer-type questions

5

3

4 x 3 = 12