UP Board Class 12 Chemistry Question Paper with Answer Key and Solutions PDF (March 4, Code 347 BZ)

The number of atoms in a body centred cubic (bcc) unit cell is

• (A) 1
• (B) 2
• (C) 4
• (D) 6

3.0 g of acetic acid is dissolved in 80 g of benzene. The molality of the solution is

• (A) 0.0625 mol kg\(^{-1}\)
• (B) 0.00625 mol kg\(^{-1}\)
• (C) 0.625 mol kg\(^{-1}\)
• (D) 6.25 mol kg\(^{-1}\)

Velocity constant for a first order reaction is \( 2 \times 10^{-3} \, s^{-1} \). The half-life period for this reaction is

• (A) \( 3.465 \times 10^3 \, s \)
• (B) \( 3.465 \times 10^2 \, s \)
• (C) \( 3.465 \times 10^1 \, s \)
• (D) \( 3.465 \times 10^{-2} \, s \)

The base not present in DNA is

• (A) Adenine
• (B) Guanine
• (C) Cytosine
• (D) Uracil

IUPAC name of CH\(_3\)-CH-CH\(_3\) is

• (A) 2-hydroxy 3-methyl butanal
• (B) 2-methyl butan-3-ol
• (C) 3-methyl butan-2-ol
• (D) methyl hydroxybutanal

Hinsberg reagent is

• (A) Ethyl oxalate
• (B) Trimethyl amine
• (C) Benzene sulphonyl chloride
• (D) Benzyl chloride

An element forms CCP lattice. If the length of its core of unit cell is 408.6 pm, then calculate the density of the element. (Atomic weight = 107.9 u)

Explain the following defects:


(i) Interstitial


(ii) F-centred

What is Kohlrausch law? Write its applications.

On dissolution of 2.0 g of a non-electrolyte in 50.0 g benzene, its freezing point decreases by 0.40 K. The freezing point depression constant of benzene is 5.12 K kg mol\(^{-1}\). Calculate the molar mass of the solute.

Explain the following:


(i) Electrophoresis


(ii) Dialysis

Explain the following:


(i) Why is the atomic size of noble gases comparatively larger?


(ii) Being almost equal in electronegativity, Nitrogen forms hydrogen bond while chlorine does not.

Justify with reasons:


(i) [NiCl\(_4\)]\(^{2-}\) is paramagnetic while [Ni(CO)\(_4\)] is diamagnetic, although both are tetrahedral.

(ii) [Fe(H\(_2\)O)\(_6\)]\(^{3+}\) is stronger paramagnetic while [Fe(CN)\(_6\)]\(^{3-}\) is weaker paramagnetic.

What are polypeptides? Explain with example.

The column of a solution of 0.05 mol L\(^{-1}\) NaOH has diameter 2.0 cm and length 100 cm. The resistance of the column of solution is 5.55 \(\times\) 10\(^3\) ohm. Calculate its resistivity, conductivity and molar conductivity.

Write short notes on the following:


(i) Tyndall Effect


(ii) Brownian Movement


(iii) Coagulation

Write the structural formula of fructose. How is it different from the structure of glucose?

Give a chemical test for differentiating the following couple of compounds:


(i) Secondary and Tertiary Amines


(ii) Methyl Amine and Dimethyl Amine


(iii) Ethylamine and Aniline

What do you understand by elevation in boiling point? Boiling point of a liquid is 350 K. On dissolving 2.0 g of a non-volatile solute in 100 g liquid, the boiling point of solution becomes 350.50 K. Calculate the molar mass of the solute. \( K_b \) for the liquid is 2.50 K kg mol\(^{-1}\).

What do you understand by order of reaction? What is the difference between the first order and zero order reaction? Following data was obtained on first order thermal decomposition of \(N_2O_5\) (g) at fixed volume:


2N\(_2\)O\(_5\) (g) \(\rightarrow\) 2N\(_2\)O\(_4\) (g) + O\(_2\) (g)

What are transition elements? Write the names and electronic configuration of the elements of the first transition series. Transition metals and their maximum compounds are paramagnetic. Explain.

Write the formulas of the following coordination compounds:


(i) Tetracarbonyl nickel (0)


(ii) Dichlorobis(ethan-1, 2-diamine) cobalt(III) chloride


(iii) Pentamine carbonato cobalt(III) chloride


(iv) Tetramine aquachloro cobalt(III) chloride

What happens when (give chemical equations only):


(i) Concentrated H\(_2\)SO\(_4\) is added in calcium fluoride?


(ii) SO\(_3\) is passed in water?


(iii) Calcium hydroxide reacts with ammonium chloride?


(iv) Concentrated sulphuric acid and copper metal is heated?


(v) Chlorine gas is passed in cold caustic soda solution?

Describe the method of preparation of dinitrogen in the laboratory and also write the chemical equations of the reactions. Write the reactions of dinitrogen with (i) oxygen and (ii) magnesium at high temperature. What is its reaction with hydrogen in presence of catalyst at 773 K temperature?

Write IUPAC names of the following:


(i) CH\(_3\)CH = CH-CH\(_3\) Br


(ii) (CH\(_3\))\(_3\)-C-CH\(_2\)(Br)


(iii) CH\(_3\)CH\(_2\)-C-CH(Cl)CH\(_2\)CH\(_3\)


(iv) (CH\(_3\))\(_2\)CBrCH\(_2\)CH\(_3\)


(v) (CH\(_3\))\(_3\)Cl

Explain with reasons:


(i) Sulphuric acid is not used in the reaction of alcohol and KI.


(ii) Haloalkanes form alkyl cyanide as chief product on reaction with KCN, while isocyanide as chief product on reaction with AgCN.


(iii) Although chlorine is an electron withdrawing group, even then it is ortho- and para-directing in aromatic electrophilic substitution reactions.

Give chemical equation for the following reactions:


(i) Oxidation of propan-1-ol with alkaline KMnO\(_4\):

How can the following changes be done? (Give chemical equations only)


(i) Propan-1-ol from ethyl magnesium chloride:

What happens when (Give chemical equations only):


(i) Acetaldehyde reacts with dilute NaOH:

Write short notes on the following:


(i) Kolbe Electrolysis: