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Maharashtra HSC Class 12 Chemistry July 2025 question paper

Maximum marks 70 · Time 3 hours

Try each question first, then open its model answer. Where the paper offers a choice, both questions are shown with OR between them.

Section A

1 mark each

  1. Select and write the correct answer for the following multiple choice type of questions :
    Q.1 (i)1 mark
    Coordination number of atoms in bcc crystal lattice is _____.

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  2. Q.1 (ii)1 mark
    The unit of Henry's Law constant is _____.

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  3. Q.1 (iii)1 mark
    pH of human blood is _____.

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  4. Q.1 (iv)1 mark
    Ideal gas expands isothermally from 20 dm320\ \mathrm{dm^{3}} to 25 dm325\ \mathrm{dm^{3}} at constant pressure of 1.5 bar; then work done in dm3\mathrm{dm^{3}} bar will be _____.

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  5. Q.1 (v)1 mark
    Correct statement about electrolysis of aqueous NaCl is _____.

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  6. Q.1 (vi)1 mark
    Rate constant of reaction is mole dm−3 sec−1\mathrm{mole\ dm^{-3}\ sec^{-1}}, the order of reaction will be _____.

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  7. Q.1 (vii)1 mark
    The correct possible general formula for interhalogen compound in the following is −-

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  8. Q.1 (viii)1 mark
    All radioactive elements are present in which of the following _____.

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  9. Q.1 (ix)1 mark
    The metal used in preparation of Grignard reagent is _____.

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  10. Q.1 (x)1 mark
    Which among the following is dicarboxylic acid −-

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  11. Answer the following questions :
    Q.2 (i)1 mark
    Write formula to calculate percent (%) atom economy of particular reaction.
  12. Q.2 (ii)1 mark
    Write name of monomer used to form nylon-6 polymer.
  13. Q.2 (iii)1 mark
    Write the total number of chiral carbon atoms present in glucose.
  14. Q.2 (iv)1 mark
    Complete the following reaction : CH3−CO−NH2+4[H]→LiAlH4, ether (H3O+)Na/C2H5OH ?+H2O\mathrm{CH_3{-}CO{-}NH_2 + 4[H] \xrightarrow[\mathrm{LiAlH_4},\ \text{ether}\,(\mathrm{H_3O^{+}})]{\mathrm{Na}/\mathrm{C_2H_5OH}}\ ? + H_2O}
  15. Q.2 (v)1 mark
    Write name of reagent used to convert phenol to Benzene.
  16. Q.2 (vi)1 mark
    Write IUPAC name for the structure shown : a benzene ring carrying a −CO−CH3\mathrm{{-}CO{-}CH_3} group and, on the adjacent ring carbon, a −Cl\mathrm{{-}Cl} atom.
  17. Q.2 (vii)1 mark
    Write oxidation state of 'Fe' in [Fe(CN)6]4−\mathrm{[Fe(CN)_6]^{4-}} complex ion.
  18. Q.2 (viii)1 mark
    When 6.0 g of O2\mathrm{O_2} reacts with ClF as per 2ClF(g)+O2(g)⟶Cl2O(g)+OF2(g)\mathrm{2ClF_{(g)} + O_{2(g)} \longrightarrow Cl_2O_{(g)} + OF_{2(g)}} The enthalpy change is 38.55 kJ. Calculate the standard enthalpy of the reaction.

Section B

2 marks each · attempt any 8

  1. Q.32 marks
    When gold crystallizes, it forms face-centered cubic cells. The unit cell edge length is 4×10−84 \times 10^{-8} cm. Calculate the density of gold. Molar mass of gold is 197 g mol−1197\ \mathrm{g\ mol^{-1}}.
  2. Q.42 marks
    Define the following terms : (a) Isotonic solution (b) Colligative properties
  3. Q.52 marks
    A solution has hydrogen ion concentration 0.01 M. Calculate pOH of the same solution.
  4. Q.62 marks
    Derive the relation between ΔH\Delta H and ΔU\Delta U for gaseous phase reaction.
  5. Q.72 marks
    What is Salt bridge? Write the functions of salt bridge.
  6. Q.82 marks
    Distinguish between order and molecularity of a reaction.
  7. Q.92 marks
    Explain anomalous behaviour of Fluorine with respect to (i) Oxyacid (ii) Nature of hydrides (iii) Electronegativity (iv) Electron gain enthalpy
  8. Q.102 marks
    Balance the following chemical reactions. (i) K2Cr2O7+KI+H2SO4⟶K2SO4+Cr2(SO4)3+H2O+I2\mathrm{K_2Cr_2O_7 + KI + H_2SO_4 \longrightarrow K_2SO_4 + Cr_2(SO_4)_3 + H_2O + I_2} (ii) K2Cr2O7+H2SO4+H2S⟶K2SO4+Cr2(SO4)3+H2O+3S\mathrm{K_2Cr_2O_7 + H_2SO_4 + H_2S \longrightarrow K_2SO_4 + Cr_2(SO_4)_3 + H_2O + 3S}
  9. Q.112 marks
    Write IUPAC names of following co-ordination ion / compound. (i) [Cu(NH3)4]2+\mathrm{[Cu(NH_3)_4]^{2+}} (ii) Na3[AlF6]\mathrm{Na_3[AlF_6]}
  10. Q.122 marks
    Complete the following reactions −- (i) CH3−CH=CH2+HBr⟶ ?\mathrm{CH_3{-}CH{=}CH_2 + HBr \longrightarrow\ ?} (ii) C2H5OH+SOCl2→Δ ?\mathrm{C_2H_5OH + SOCl_2 \xrightarrow{\Delta}\ ?}
  11. Q.132 marks
    Write chemical reactions for the preparation of phenol from isopropyl benzene.
  12. Q.142 marks
    Write a note on Haloform reaction.

Section C

3 marks each · attempt any 8

  1. Q.153 marks
    A mixture of benzene and toluene contains 30% by mass of toluene. At 30°C, vapour pressure of pure toluene is 36.7 mmHg and that of pure benzene is 118.2 mmHg. Assuming that the two liquids form ideal solution, calculate partial pressure of each constituent in the above solution at 30°C.
  2. Q.163 marks
    Define : (i) Buffer solution (ii) Solubility product (iii) Common ion effect
  3. Q.173 marks
    Calculate maximum work done when 32 g of oxygen expanded isothermally and reversibly from pressure 2 bar to 1 bar at 298 K.
  4. Q.183 marks
    What is zero order reaction? Derive integrated rate law equation for zero order reaction.
  5. Q.193 marks
    (a) Write structures of : (i) Chlorous acid (ii) Perchloric acid (b) Write uses of Helium
  6. Q.203 marks
    (a) What is Lanthanoid contraction? (b) Compounds of 'd' block elements are coloured in solid state as well as in an aqueous state. Explain.
  7. Q.213 marks
    (a) Write the representation of sodium hexacyanoferrate (III) (b) Write type of hybridization and magnetic behaviour of the following −- (i) [Co(NH3)6]3+\mathrm{[Co(NH_3)_6]^{3+}} (ii) [NiCl4]2−\mathrm{[NiCl_4]^{2-}}
  8. Q.223 marks
    Convert – (Indicate by reaction) (a) Acetic acid to ethyl acetate (b) Acetaldehyde to acetaldoxime (c) Acetone to propane
  9. Q.233 marks
    (a) What is the action of following on ethylamine −- (i) Hinsberg reagent (ii) Nitrous acid (b) Write increasing order of basicity for CH3NH2\mathrm{CH_3NH_2}, (CH3)2NH\mathrm{(CH_3)_2NH} and (CH3)3N\mathrm{(CH_3)_3N}
  10. Q.243 marks
    (a) What are monosaccharides? (b) Draw Zwitter ion structure of α\alpha amino acid. (c) Write name of components of the nucleotide monomers.
  11. Q.253 marks
    (a) Write chemical reaction for preparation of Teflon. (b) Write structure of monomer of natural rubber. (c) Give two uses of high density polyethene [HDP].
  12. Q.26 (i)3 marks
    Explain the following terms : (a) Sustainable development (b) Nanomaterial
  13. Q.26 (ii)
    Name the gamma isomer of BHC.

Section D

4 marks each · attempt any 3

  1. Q.27 (i)4 marks
    Distinguish between crystalline and amorphous solids.
  2. Q.27 (ii)
    Explain bleaching action of chlorine in the presence of moisture.
  3. Q.284 marks
    (a) Draw neat and labelled diagram of standard hydrogen electrode. (b) Calculate e.m.f. of the following cell. Mg∣Mg(aq)2+∥Ag(aq)+∣Ag\mathrm{Mg \mid Mg^{2+}_{(aq)} \parallel Ag^{+}_{(aq)} \mid Ag} If EMg∘=−2.37E^{\circ}_{\mathrm{Mg}} = -2.37 Volt and EAg∘=0.8E^{\circ}_{\mathrm{Ag}} = 0.8 Volt.
  4. Q.29 (i)4 marks
    State whether the following reaction is spontaneous or non spontaneous if ΔH=50\Delta H = 50 kJ and ΔS=−130 JK−1\Delta S = -130\ \mathrm{JK^{-1}} at 250 K.
  5. Q.29 (ii)
    (b) Explain optical activity in 2-chlorobutane. (c) Write full name of DDT.
  6. Q.30 (i)4 marks
    Define Co-ordination number.
  7. Q.30 (ii)
    (b) Write note on Reimer-Tieman reaction. (c) Write structural formula for methyl vinyl ether.
  8. Q.31 (i)4 marks
    Explain Aldol condensation reaction of ethanal.
  9. Q.31 (ii)
    Write four properties of interstitial compounds of transition elements.