Chemistry Patna Set 2 2014-2015 Science (English Medium) Class 12 Question Paper Solution

Account for the following:

Cu⁺² salts are coloured, while Zn²⁺ salts are white.

Which would undergo S_N1 reaction faster in the following pair and why?

How much charge is required for the reduction of 1 mol of Zn²⁺ to Zn?

Write the dispersed phase and dispersion medium of butter.

Write the IUPAC name of the given compound:

Write the structures of the following molecules: H₂SO₃

Write the structures of the following molecules: XeOF₄

Write down the IUPAC name of the complex [Pt(en)₂Cl₂]²⁺. What type of isomerism is shown by this complex?

Using IUPAC norms write the formulate for the following coordination compounds : Hexaamminecobalt (III) chloride

Using IUPAC norms write the formulate for the following coordination compounds :

Potassium tetrachloridonickelate (II)

What is rate of reaction?

Write two factors that affect the rate of reaction.

Arrange the following in increasing order of their basic strength :

C₆H₅ – NH₂, C₆H₅ – CH₂ – NH₂, C₆H₅ – NH – CH₃

Arrange the following in increasing order of their basic strength :

Why does a solution containing non-volatile solute have higher boiling point than the pure solvent ?

Why is elevation of boiling point a colligative property?

What is the principle behind the zone refining of metals?

What is the role of silica in the extraction of copper?

How is 'cast iron' different from 'pig iron'?

Account for the following:

N₂ is less reactive at room temperature.

Give reasons for the following : H₂Te is the strongest reducing agent amongst all the hydrides of Group 16 elements.

Account for the following:

Helium is used in diving apparatus.

Write the hybridization and shape of the following complexe : [CoF₆]^3–

(Atomic number : Co = 27, Ni = 28)

Write the hybridization and shape of the following complexe : [Ni(CN)₄]^2–

^{(Atomic number : Co = 27, Ni = 28)}

Out of NH₃ and CO, which ligand forms a more stable complex with a transition metal and why?

How do you convert the following: C₆H₅CONH₂ to C₆H₅NH₂

How do you convert the following:

Aniline to phenol

How do you convert the following: Ethanenitrile to ethanamine

Write the chemical equations involved when aniline is treated with the following reagents:

Br₂ water

Write the chemical equations involved when aniline is treated with the following reagents:

CHCI₃ + KOH

Write the chemical equations involved when aniline is treated with the following reagents: HCI

Write the names and structure of the monomers of the following polymers: Buna − S

Write the names and structures of the monomers of the following polymers: Glyptal

Write the names and structures of the monomers of the following polymers: Polyvinyl chloride

Write the product obtained when D-glucose reacts with H₂N − OH.

Amino acids show amphoteric behaviour. Why?

Why Vitamin C cannot be stored in our body ?

Calculate the freezing point of the solution when 31 g of ethylene glycol (C₂H₆O₂) is dissolved in 500 g of water.

(K_f for water = 1.86 K kg mol^–1)

Define the following term: Primitive unit cells

Define the following term

Schottky defect

Define the following term: Ferromagnetism

Write the structure of the major product in each of the following reaction :

Write the structure of the major product in each of the following reaction :

Write the structure of the major product in each of the following reaction :

Give reasons for the following : Phenol is more acidic than ethanol.

Give reasons for the following : Boiling point of ethanol is higher in comparison to methoxymethane.

 Give reasons for the following:

(CH₃)₃C–O–CH₃ on reaction with HI gives (CH₃)₃C–I and CH₃–OH as the main products and not (CH₃)₃C–OH and CH₃–I.

The rate constant of a first order reaction increases from 2 × 10⁻² to 4 × 10⁻² when the temperature changes from 300 K to 310 K. Calculate the energy of activation (E_a).

(log 2 = 0.301, log 3 = 0.4771, log 4 = 0.6021)

Define the following term : Brownian movement

Define the following term :

Peptization

Define the following term : Multimolecular colloids

Seeing the growing cases of diabetes and depression among young children, Mr Lugani, the principal of one reputed school, organised a seminar in which he invites parents and principals. They all resolved this issue by strictly banning junk food in schools and introducing healthy snacks and drinks like soup, lassi, milk etc. in school canteens. They also decided to make compulsory half an hour of daily physical activities for the students in the health survey in most of the school and discovered a tremendous improvement in the health of the students

After reading the above passage, answer the following questions:

(i) What are the values (at least two) displayed by Mr Lugani?

(ii) As a student, how can you spread awareness about this issue?

(iii) What are antidepressant drugs? Give an example.

(iv) Name the sweetening agent used in the preparation of sweets for a diabetic patient.

Calculate e.m.f. and ∆G for the following cell:

Mg (s) |Mg²⁺ (0.001M) || Cu²⁺ (0.0001M) | Cu (s)

`"Given :" E_((Mg^(2+)"/"Mg))^0=−2.37 V, E_((Cu^(2+)"/"Cu))^0=+0.34 V.`

The conductivity of 0.20 mol L⁻¹ solution of KCl is 2.48 × 10⁻² S cm⁻¹. Calculate its molar conductivity and degree of dissociation (α). Given λ⁰ (K⁺) = 73.5 S cm² mol⁻¹ and λ⁰ (C1⁻) = 76.5 S cm² mol⁻¹.

What type of battery is mercury cell? Why is it more advantageous than dry cell?

Account for the following :

Zr and Hf have almost similar atomic radii.

Give reasons: Transition metals show variable oxidation states.

Account for the following:

Cu⁺ ion is unstable in aqueous solution.

Complete the following equations : 2 MnO₂ + 4 KOH + O₂ →

Complete the following equations : 2 Na₂CrO₄ + 2 H ⁺ →​

From the given data of E⁰ values, answer the following questions :

(1) Why is `E_(((Cu^(2+))/(Cu)))` value exceptionally positive

(2) Why is `E_(((Mn^(2+))/(Mn)))` value is highly negative as compared to other elements

(3) Which is the stronger reducing agents Cr²⁺ or Fe²⁺ ? Give Reason.

Why do actinoids show a wide range of oxidation states?

Write on similarity between the chemistry of lanthanoids and actinoids.

A compound 'A' of molecular formula C₂H₃OCl undergoes a series of reactions as shown below. Write the structures of A, B, C and D in the following reactions :

Distinguish between:

C₆H₅-COCH₃ and C₆H₅-CHO

Distinguish between the following : Benzoic acid and methyl benzoate

Write the structure of 2-methylbutanal.

Write the structures of the main products when acetone (CH₃ − CO − CH₃) reacts with the following reagent :

Zn − Hg/conc. HCl

Write the structures of the main products when acetone (CH₃ − CO − CH₃) reacts with the following reagent :

H₂N − NHCONH₂/H⁺

Write the structures of the main products when acetone (CH₃ − CO − CH₃) reacts with the following reagents :

CH₃MgBr and then H₃O⁺

Arrange the following in the increasing order of their boiling points : C₂H₅OH, CH₃ − CHO, CH₃ − COOH

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

CH₃CH₂CHO and CH₃CH₂COCH₃