Maharashtra Board Class 12 Chemistry Question Paper 2023 with Answer Key

The relation between radius of sphere and edge length in body centered cubic lattice is given by formula:

• (A) \( \sqrt{3}r = 4a \)
• (B) \( r = \frac{\sqrt{3}}{4} \times a \)
• (C) \( r = \frac{\sqrt{5}}{4} \times a \)
• (D) \( r = \frac{\sqrt{2}}{4} \times a \)

The pH of weak monoacidic base is 11.2, its OH\(^-\) ion concentration is:

• (A) \( 1.585 \times 10^{-3} \) mol dm\(^{-3}\)
• (B) \( 3.010 \times 10^{-11} \) mol dm\(^{-3}\)
• (C) \( 3.010 \times 10^{-3} \) mol dm\(^{-3}\)
• (D) \( 1.585 \times 10^{-11} \) mol dm\(^{-3}\)

Which of the following correctly represents the integrated rate law equation for a first order reaction in the gas phase?

• (A) \( k = \frac{2.303}{t} \times \log \frac{P_i}{P_i - P} \)
• (B) \( k = \frac{2.303}{t} \times \log \frac{P_i}{2P_i - P} \)
• (C) \( k = \frac{2.303}{t} \times \log \frac{2P_i}{P_i - P} \)
• (D) \( k = \frac{2.303}{t} \times \log \frac{P_i - P}{2P_i} \)

The spin only magnetic moment of Mn\(^{2+}\) ion is:

• (A) 4.901 BM
• (B) 5.916 BM
• (C) 3.873 BM
• (D) 2.846 BM

The correct formula of a complex having IUPAC name Tetraaminedibromoplatinum (IV) bromide is:

• (A) [PtBr\(_2\) (NH\(_3\))\(_4\)] Br
• (B) [PtBr\(_3\) (NH\(_3\))\(_4\)] Br
• (C) [PtBr\(_2\) (NH\(_3\))\(_4\)] Br\(_2\)
• (D) [PtBr\(_3\) (NH\(_3\))\(_4\)] Br\(_2\)

The allylic halide, among the following is:

• (A) \( R - CH - R \)
• (B) \( CH_2 - CH - X \)
• (C) \( C_6H_5 - X \)
• (D) \( CH_2 - CH - CH_2 - X \)

The product of the following reaction is:

• (A) \( CH_3 - CH = CH_2 - CH_2 - OH \)
• (B) \( CH_3 - CH - CH_2 - CH_2 - OH \)
• (C) \( CH_3 - CH_2 - CH_2 - COOH \)
• (D) \( CH_3 - CH = CH_2 - COOH \)

Ozonolysis of 2, 3 dimethyl but-2-ene, followed by decomposition by Zn dust and water gives:

• (A) acetaldehyde
• (B) propionaldehyde and acetone
• (C) acetaldehyde and butyraldehyde
• (D) acetalaldehyde and butyraldehyde

The glycosidic linkage present in maltose is:

• (A) \( \alpha, \beta - 1, 2 \)-glycosidic linkage
• (B) \( \alpha, \beta - 1, 4 \)-glycosidic linkage
• (C) \( \beta - 1, 4 \)-glycosidic linkage
• (D) \( \alpha - 1, 4 \)-glycosidic linkage

The monomer of natural rubber is:

• (A) Isoprene
• (B) Acrylonitrile
• (C) \( \varepsilon \)-Caprolactam
• (D) Tetrafluoroethylene

Write the name of the product formed by the action of \( LiAlH_4 \) ether on acetamide.

Write the structure of the product formed when chlorobenzene is treated with sodium metal in the presence of dry ether.

Write the chemical composition of cryolite.

Write the name of the platinum complex used in the treatment of cancer.

Write the SI unit of cryoscopic constant.

Write the correct condition for spontaneity in terms of Gibbs energy.

Calculate the molar conductivity for 0.5 M BaCl_2 if its conductivity at 298K is 0.01 \( \Omega^{-1} cm^{-1} \).

Distinguish between lanthanides and actinides.

Calculate the mole fraction of solute, if the vapour pressure of pure benzene at certain temperature is 640 mmHg and vapour pressure of solution of a solute in benzene is 600 mmHg.

Define Green chemistry. Write two advantages of nanoparticles and nanotechnology.

Explain the following terms:

Substitutional impurity defect
Interstitial impurity defect

Write the chemical reactions for the following:

Chlorobenzene is heated with fuming H\(_2\)SO\(_4\)
Ethyl bromide is heated with silver acetate

Define: Acidic buffer solution. Write the relationship between solubility and solubility product for PbI\(_2\).

What is the action of the following reagents on ethylamine?

Chloroform and caustic potash
Nitrous acid

Calculate standard Gibbs energy change at 25°C for the cell reaction \[ Cd(s) + Sn^{2+}_{(aq)} \rightleftharpoons Cd^{2+}_{(aq)} + Sn(s) \]
Given: \[ E^\circ_{cd} = -0.403V, \quad E^\circ_{sn} = -0.136V \]

Write the chemical reaction for the preparation of glucose from sucrose. Write structure of D-ribose.

Define Extensive property. Calculate the work done during the expansion of 2 moles of an ideal gas from 10 dm^3 to 20 dm^3 at 298 K in vacuum.

Write the reactions for the formation of nylon 6,6 polymer.

Draw structures of the following compounds:

Chloric acid
Peroxy disulfuric acid
 

Define Osmosis.
How will you determine the molar mass of a non-volatile solute by elevation of boiling point?

Convert the following:
i. Ethyl alcohol into ethyl acetate

ii. Phenol into benzene

iii. Diethyl ether into ethyl chloride

A weak monobasic acid is 10% dissociated in 0.05 M solution. What is the percent dissociation in 0.15 M solution?

Explain the dehydrohalogenation reaction of 2-chlorobutane. Write use and environmental effect of CFC.

2000 mmol of an ideal gas expanded isothermally and reversibly from 20 L to 30 L at 300 K, calculate the work done in the process (R = 8.314 J K\(^{-1}\) mol\(^{-1}\)).

What are interstitial compounds? Give the classification of alloys with examples.

Draw labelled diagram of H\(_2\) - O\(_2\) fuel cell. Write two applications of fuel cell.

Explain formation of [CoF\(_6\)]\(^{3-}\) complex with respect to
i. Hybridisation
ii. Magnetic properties
iii. Inner/outer complex
iv. Geometry

What is Pseudo first order reaction? Derive integrated rate law equation for zero order reaction.

Explain Aldol condensation of ethanal.

Explain anomalous behaviour of oxygen in group 16 with respect to:
i. Atomicity
ii. Magnetic property
iii. Oxidation state

Write chemical reactions for the following conversions:
i. Acetic acid into acetic anhydride
ii. Acetic acid into ethyl alcohol
Write IUPAC name and structure of methylphenylamine.

Show that, time required for 99.9% completion of a first order reaction is three times the time required for 90% completion.
Give electronic configuration of Gd (Z = 64).
Write the name of nano structured material used in car tyres to increase the life of tyres.

Derive relationship between \(\Delta H\) and \(\Delta U\) for gaseous reaction.
Define: Vulcanization
What is peptide bond?

Silver crystallizes in fcc structure. If edge length of unit cell is 400 pm, calculate density of silver (Atomic mass of Ag = 108).
Write a note on Halform reaction.

Define: Stereoisomers.
Give cis and trans isomers of \([Co(NH_3)_4Cl_2]^+\).
What is reference electrode?

Write Dow process for preparation of Phenol. What is the action of bromine water on phenol?
Give reason: Group 16^th elements have lower ionization enthalpy compared to group 15^th elements.
Write two uses of dioxygen.