Chemistry Delhi Set 1 2013-2014 Commerce (English Medium) Class 12 Question Paper Solution

Give one example each of 'oil in water' and 'water in oil' emulsion.

Which reducing agent is employed to get copper from the leached low-grade copper ore?

Which of the following is a more stable complex and why ?

Write the IUPAC name of the compound.

Which of the following isomers is more volatile:

o-nitrophenol or p-nitrophenol?

What are isotonic solutions? Explain with one example.

Arrange the following.

In increasing order of solubility in water, C₆H₅NH₂, (C₂H₅)₂NH, C₂H₅NH₂

Which of the two components of starch is water soluble?

An element with density 11.2 g cm^–3 forms a f.c.c. lattice with edge length of 4 × 10^–8 cm.
Calculate the atomic mass of the element.
(Given : N_A = 6.022 × 10²³ mol^–1)

Examine the given defective crystal:

Answer the following questions :
(i) What type of stoichiometric defect is shown by the crystal?
(ii) How is the density of the crystal affected by this defect?
(iii) What type of ionic substances show such defect?

Calculate the mass of a compound (molar mass = 256 g mol⁻¹) to be dissolved in 75 g of benzene to lower its freezing point by 0.48 K (K_f = 5.12 K kg mol⁻¹).

Define an ideal solution and write one of its characteristics.

Write two differences between 'order of reaction' and 'molecularity of reaction'.

Outline the principles behind the refining of metals by the following methods:

Zone refining method

Outline the principles behind the refining of metals by the following methods:

Chromatographic method

Complete the following chemical equations :

Ca₃P₂ + H₂O →

Complete the following chemical equations :

Cu + H₂SO₄(conc.) →

Write the IUPAC name of the complex [Cr(NH₃)₄Cl₂]⁺. What type of isomerism does it exhibit?

Which alkyl halide from the following pair is chiral and undergoes faster S_N2 reaction?

Out of S_N1 and S_N2, which reaction occurs with

(a) Inversion of configuration
(b) Racemisation

Draw the structure of major monohalo product in each of the following reactions :

Draw the structure of major monohalo product in each of the following reactions :

In reference to Freundlich adsorption isotherm, write the expression for adsorption of gases on solids in the form of an equation.

Write an important characteristic of lyophilic sols.

Based on the type of particles of dispersed phase, give one example each of associated colloid and multimolecular colloid.

Write the structures of the following molecules: XeOF₄

Draw the structure of the following:

H₂SO₄

Write the structural difference between white phosphorus and red phosphorus.

Account for the following:

PCl₅ is more covalent than PCl₃.

Account for the following :

Iron on reaction with HCl forms FeCl₂ nd not FeCl₃.

The two O−O bond lengths in the ozone molecule are equal.

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)

Give two examples of macromolecules that are chosen as drug targets

Explain the term Antiseptics

Why is use of aspartame limited to cold foods and drinks?

Deficiency of which vitamin causes night-blindness?

Name the base that is found in nucleotide of RNA only.

Glucose on reaction with HI gives n-hexane. What does it suggest about the structure of glucose?

After the ban on plastic bags, students of a school decided to make people aware of the harmful effects of plastic bags on the environment and Yamuna River. To make the awareness more impactful, they organised a rally by partnering with other schools and distributed paper bags to vegetable vendors, shopkeepers and departmental stores. All the students pledged not to use polythene bags in the future to save the Yamuna River.

After reading the above passage, answer the following questions:
(i) What values are shown by the students?
(ii) What are bio-degradable polymers? Give one example.
(iii) Is polythene a condensation or an addition polymer?

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

Write the equation involved in the following reaction:

Reimer-Tiemann reaction

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

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

How will you convert the following?

Nitrobenzene into aniline

How will you convert Ethanoic acid into methanamine

How will you convert the following?

Aniline into N−phenylethanamide

Define the following terms :

Limiting molar conductivity

Define the following term:

Fuel cell

Resistance of a conductivity cell filled with 0.1 mol L⁻¹ KCl solution is 100 Ω. If the resistance of the same cell when filled with 0.02 mol L⁻¹ KCl solution is 520 Ω, calculate the conductivity and molar conductivity of 0.02 mol L⁻¹KCl solution. The conductivity of 0.1 mol L⁻¹ KCl solution is 1.29 × 10⁻² Ω⁻¹ cm⁻¹.

State Faraday's first law of electrolysis.

How much charge in terms of Faraday is required for the reduction of 1 mol of Cu²⁺ to Cu?

Calculate emf of the following cell at 298 K:
Mg(s) | Mg²⁺(0.1 M) || Cu²⁺ (0.01) | Cu(s)
[Given E^o_cell = +2.71 V, 1 F = 96500 C mol^–1]

How do you prepare:

K₂MnO₄ from MnO₂?

How do you prepare:

Na₂Cr₂O₇ from Na₂CrO₄?

Account for the following:

Mn²⁺ is more stable than Fe²⁺ towards oxidation to +3 state.

Account for the following 

The enthalpy of atomisation is lowest for Zn in 3d series of the transition elements.

How do you prepare:

Actinoid elements show wide range of oxidation states.

Name the elements of 3d transition series that show maximum number of oxidation states. Why does this happen?

Which transition metal of 3d series has positive E° (M²⁺/M) value and why?

Out of Cr³⁺ and Mn³⁺, which is a stronger oxidising agent and why?

Name a member of the lanthanoid series that is well-known to exhibit +2 oxidation state.

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

Write the products of the following reactions:

Write the products of the following reactions:

Write the products of the following reactions:

Give simple chemical tests to distinguish between the following pair of compounds:

Benzaldehyde and Benzoic acid

Propanal and Propanone

Account for the following:

CH₃CHO is more reactive than CH₃COCH₃ towards reaction with HCN.

Account for the following:

Carboxylic acid is a stronger acid than phenol.

Write the equations involved in the following reactions :

Wolff-Kishner reduction

Write the chemical equations to illustrate the following name reactions:

Aldol condensation

Write the chemical equations to illustrate the following name reaction: 

Cannizzaro’s reaction