Chemistry All India Set 2 2013-2014 Commerce (English Medium) Class 12 Question Paper Solution

Why is adsorption always exothermic?

Name the method used for the refining of Nickel metal.

Why does NO₂ dimerise?

Based on molecular forces, what type of polymer is neoprene?

What are the products of hydrolysis of maltose?

Write the structure of 4-chloropentan-2-one.

Identify the chiral molecule in the following pair :

The conversion of primary aromatic amines into diazonium salts is known as ___________

Write the names of monomers used for getting the following polymers

Terylene

Write the names and structure of the monomers of the following polymers: Nylon-6, 6

Describe the roles of the following: SiO₂ in the extraction of copper from copper matte

Describe the roles of the following: NaCN in froth floatation process

Complete the following equations: Ag+PCl₅ →

Complete the following equations: CaF₂+H₂SO₄ →

Draw the structures of the following molecules: XeF₄

Draw the structures of the following:
(1) HClO₄
(2) H₃PO₃

Write the type of magnetism observed when the magnetic moments are oppositely aligned and cancel out each other.

Which stoichiometric defect does not change the density of the crystal?

Define terms: Fuel cell

Define limiting molar conductivity.

Write the mechanism of the following reaction :

For a chemical reaction R → P, the variation in the concentration (R) vs. time (t) plot is given as:

(i) Predict the order of the reaction.

(ii) What is the slope of the curve ?

(iii) Write the unit of rate constant for this reaction.

An element with density 2.8 g cm^–3 forms a f.c.c. unit cell with edge length 4 x 10^–8 cm. Calculate the molar mass of the element.

(Given : N_A = 6.022 x 10²³ mol ^–1)

Write the equation involved in the following reaction:

Reimer-Tiemann reaction

Write the equations involved in the following reactions : Williamson synthesis

Define the following term:

Glycosidic linkage

Define the following terms:

Invert sugar

Define the following terms:

Oligosaccharides

On the occasion of World Health Day, Dr. Satpal organized a ‘health camp’ for the poor farmers living in a nearby village. After check-up, he was shocked to see that most of the farmers suffered from cancer due to regular exposure to pesticides and many were diabetic. They distributed free medicines to them. Dr. Satpal immediately reported the matter to the
National Human Rights Commission (NHRC). On the suggestions of NHRC, the government decided to provide medical care, financial assistance, setting up of super-speciality hospitals for treatment and prevention of the deadly disease in the affected villages all over India.

(i) Write the values shown by

(a) Dr. Satpal

(b) NHRC

(ii) What type of analgesics are chiefly used for the relief of pains of terminal cancer ?

(iii) Give an example of artificial sweetener that could have been recommended to diabetic patients

Give reason for the following:

Primary amines have higher boiling point than tertiary amines.

Give reasons for the following:

Aniline does not undergo Friedel- Crafts reaction.

Give reasons for the following: (CH₃)₂NH is more basic than (CH₃)₃N in an aqueous solution.

Give the structures of A, B and C in the following reactions :

Give the structures of A, B and C in the following reactions :

Draw the structures of major monohalo products in each of the following reactions :

Draw the structures of major monohalo products in each of the following reactions :

Which halogen compound in each of the following pairs will react faster in S_N2 reaction CH₃Br or CH₃I

Which halogen compound in each of the following pairs will react faster in S_N2 reaction

(CH₃)₃ C – Cl or CH₃ – Cl

Calculate Δ_rG^° for the reaction 

Mg (s) + Cu²⁺ (aq) → Mg²⁺ (aq) + Cu (s)

Given : E^°_cell = + 2.71 V, 1 F = 96500 C mol^–1

The following data were obtained during the first order thermal decomposition of SO₂Cl₂ at a constant volume :

SO₂Cl₂ (g) → SO₂ (g) + Cl₂ (g)

Calculate the rate constant.

(Given : log 4 = 0.6021, log 2 = 0.3010)

What are emulsions?

What are their different types emulsions? Give one example of each type.

Give reasons for the following : (CH₃)₃ P = O exists but (CH₃)₃ N = O does not.

Give reasons for the following : Oxygen has less electron gain enthalpy with negative sign than sulphur.

Give reasons for the following : H₃PO₂ is a stronger reducing agent than H₃PO₃.

Write the IUPAC name of the complex [Cr(NH₃)₄ Cl₂]Cl.

What type of isomerism is exhibited by the complex [Co(en)₃]³⁺?

(en = ethane-1,2-diamine)

[NiCl₄]²⁻ is paramagnetic, while [Ni(CO)₄] is diamagnetic, though both are tetrahedral. Why? (Atomic number of Ni = 28)

Write the products formed when CH₃CHO reacts with the following reagents : HCN

Write the products formed when CH₃CHO reacts with the following reagents : H₂N – OH

Write the products formed when CH₃CHO reacts with the following reagents: CH₃CHO in the presence of dilute NaOH

Give simple chemical tests to distinguish between the following pairs of compounds:  Benzoic acid and Phenol

Propanal and Propanone

Account for the following : Cl – CH₂COOH is a stronger acid than CH₃COOH.

Why carboxylic acid does not give reactions of carbonyl group?

Write the chemical equations to illustrate the following name reactions : Rosenmund reduction

Write the chemical equations to illustrate the following name reaction: 

Cannizzaro’s reaction

Out of CH₃CH₂ – CO – CH₂ – CH₃ and CH₃CH₂ – CH₂ – CO – CH₃, which gives iodoform test?

Define the following terms : Molarity

Define the following terms : Molal elevation constant (K_b)

A solution containing 15 g urea (molar mass = 60 g mol^–1) per litre of solution in water has the same osmotic pressure (isotonic) as a solution of glucose (molar mass = 180 g mol^–1) in water. Calculate the mass of glucose present in one litre of its solution.

What type of deviation is shown by a mixture of ethanol and acetone? Give reason.

A solution of glucose (molar mass = 180 g mol^–1) in water is labelled as 10% (by mass). What would be the molality and molarity of the solution ? (Density of solution = 1.2 g mL^–1)

Complete the following equations:Cr₂O₇^2- + 2OH^- →

Complete the following equations : MnO₄- + 4H⁺ + 3e^- →

Account for the following :

Zn is not considered as a transition element.

How would you account for the following: Transition metals form complex compounds.

Account for the following:

E° value for the Mn³⁺/Mn²⁺ couple is much more positive than that for Cr³⁺/Cr²⁺.

With reference to structural variability and chemical reactivity, write the differences between lanthanoids and actinoids

Name a member of the lanthanoid series which is well known to exhibit +4 oxidation state.

Complete the following equation : MnO₄^- + 8H⁺ + 5e^- →

Out of Mn³⁺ and Cr³⁺, which is more paramagnetic and why ?

(Atomic nos. : Mn = 25, Cr = 24)