a. Fill in the blanks by choosing the appropriate word/words from those given in the brackets:
(bent, unit cell, lattice points, linear, distorted, tetrahedral, trigonal planar, octahedral, positive, negative,caprolactum, adipic acid,hexamethylenediamine ,vinyl chloride, phthalic acid)
(i) A crystal lattice, a built of repetitive units is called ______________.
(ii)
(iii) Free energy changes for a non-spontaneous reaction are _____________.
(iv) Nylon6,6 is condensation polymer of ______________ and _____________.
b. Complete the following statements by selecting the correct alternative from the choices given:
(i) The rate of first order reaction, when the concentration of a reactant is 10–1 mol L–1, is 2 x 10–4 mol L–1 sec–1. What will be the rate of the reaction when the concentration of the reactant is 10–2 mol L–1?
(ii) For a reversible reaction, if the concentration of the reactants is doubled, then the equilibrium constant will be(1) doubled.
(2) the same.
(3) halved.
(4) one fourth.
(iii) The number of optical isomers possible for a compound with two different asymmetric carbons is
(1) 8.
(2) 4.
(3) 6.
(4) 2.
(iv) pKa values of four acids at 25°C are given below. Identify the strongest acid.
(1) 3
(2) 3.5
(3) 4
(4) 5
c. Match the following:
(i) Acetamide | (a) Rosenmund reaction |
(ii) Barium sulphate | (b) Ice-like crystals |
(iii) Ethyl ethanoate | (c) Dimerisation |
(iv) Glacial acetic acid | (d) Fruity smell |
(d) Answer the following questions:
(i) A peeled egg swells when placed in water while it shrinks when placed in the concentrated NaCl solution. Why?
(ii) What is the utility of the Le-Chatelier’s principle?
(iii) What happens to the pH when a few drops of acid or alkali are added to CH3COONH4?
(iv) How much charge is required for the reduction of 1 mole of Cu2+ to Cu?
(a)
(b)
(i) (3)
Explanation:
(ii) (2)
Explanation: The value of the equilibrium constant for a reaction always depends only upon the temperature of the reaction and is independent of the concentrations of the reactants with which we start or the direction from which the equilibrium is approached.
(iii) (2)
Explanation:
Number of optical isomers = 2n, where n is the number of asymmetric carbon atoms.
∴ Number of optical isomers = 22 = 4
(iv) (1)
Explanation: Lower the pKa value, stronger is the acid.
(c)
(i) – (c), (ii) – (a), (iii) – (d), (iv) – (b)
(d)
(i) A peeled egg swells when placed in water due to endosmosis. It happens because the solution inside the egg is the concentrated one. However, it shrinks when it is placed in the concentrated NaCl solution due the process of exo-osmosis.
(ii) The Le-Chatelier’s principle can be used to predict the favourable conditions for the maximum yield in many industrial processes such as the manufacture of NH3 by the Haber’s process and the manufacture of H2SO4 by the contact’s process.
(iii) When a few drops of acid or alkali are added to CH3COONH4, it acts as a buffer. Hence, there is no change in the pH on adding a small amount of the acid or base.
(iv) The reduction reaction involved is:
Cu2+ + 2e– → Cu
∴ the charge required for the reduction of one mole of Cu2+ to Cu = 2F = 2 x 96500C = 193000 C.
It is observed that the rate of a chemical reaction doubles with every 10ºC rise in the temperature. If this generalisation holds for a reaction in the temperature ranged 298K─ 308K, what would be the value of the activation energy for this reaction (R = 8.314JK–1mole–1)?
How does a homogenous catalyst and a heterogeneous catalyst work?
A homogenous catalyst enters into chemical combination with one or more reactants forming an intermediate compound. This intermediate compound then combines with one of the reactants to form the product and regenerate the catalyst.
In case of heterogeneous catalysis, the gaseous reactants first get chemisorbed on the surface of the catalyst after getting diffused towards the catalyst. The reactants formed the products, which get absorbed on the catalyst’s surface and finally desorbed.
(a) Antiseptics are the chemicals used to prevent the growth of microorganisms or to kill them but these are not harmful to animal tissues. Examples, Furacin and Soframycin
Disinfectants are the chemicals which are used to kill microorganisms but these are harmful to the animal tissues. Examples, phenol and chlorine
(b) Detergents contains calcium and magnesium salts of sulphonic acids which are soluble even in hard water but soaps are not soluble in hard water.
(a) What is meant by denatured spirit?
(b) Arrange the following alcohols in order of increasing reactivity towards Lucas reagent: -
Tertiary butyl alcohol, Secondary butyl alcohol, Butanol-1
(a) When ethyl alcohol is made unfit for drinking purposes by adding poisonous and nauseating materials like methanol or pyridine etc. the process is called denaturing and the spirit formed is called denatured spirit.
(b) Butanol-1 < Secondary butyl alcohol < Tertiary butyl alcohol
(a) 1,3-Butadiene and styrene
(b) Hexamethylenediamine and adipic acid
Give two methods for the preparation of glucose?
Write chemical reaction for the preparation of phenol from chlorobenzene.
Explain why phenols do not undergo substitution of the –OH group like alcohols.
In alcohols, O-atom contains 2 lone pairs of electrons. So, they act as weak bases and they are replaced to get a substitution product. While in phenols, phenoxide ion is resonance stabilized and phenol releases H+ ions. Hence substitution reaction is not possible.
Write the expression for average and instantaneous rates for the following reaction
Calculate the boiling point of a solution of urea prepared by dissolving 10.36 gm of urea in 250 gm of water on a hill station where pure water boils at 99.82°C. The Kb of water is 0.513°C Kg mol–1.
Find mole fraction of each of the component in a solution containing 25% water, 25% ethanol and 50% acetic acid by mass.
The edge length of unit cell of a metal having molecular weight 75 g/mol is 5 Å, which crystallises in cubic lattice. The density of metal is 2 g/cc. Calculate the radius of metal atom. (Given: NA = 6 x 1023).
(a)
(b)
(a) Arrange the following in increasing order of their basic strength: -
(i) Triethylamine, ethylamine and ammonia.
(ii) p-nitroaniline, aniline and p-toludine.
(b)Boiling point of amines is lower than those of the alcohols and carboxylic acids of comparable molecular masses. Give reason.
(i) Ammonia < Triethylamine < Ethylamine
(ii) Aniline < p-nitroaniline < p-toludine
Give the reactions involved in the reduction of iron oxide to give iron in a blast furnace.
(i) Why is sulphuric acid also known as oil of vitriol?
(ii) Draw the structures of XeF4 and XeF2.
(iii) Write a balanced equation for each of the following reactions:
(i) It is known as oil of vitriol due to its oily appearance and the fact that it was obtained by the distillation of green vitriol (FeSO4.7H2O).
(ii)
On passing excess of SO2 gas through lime water, its milkiness disappears due to the formation of calcium bisulphate, which is soluble.
(i) Draw resonating structures of N2O4
(ii) Explain by giving reasons that why:
(ii)
(i) Give an example (equation) for each of the following name reactions:
(1) Cannizzaro reaction
(2) Wolf-Kishner reaction
(3) Schotten Baumann reaction
(ii) Explain:
(1) Use of carbylamine reaction
(2) Methyl amine is a stronger base than ammonia
(ii)
(1)The carbylamine reaction is used to distinguish between 1º amines and 2º or 3º amines. Both 1º aliphatic and aromatic amines give this reaction. They form foul smelling isocyanide on reaction with chloroform and alc. KOH.
(2) Electron donors are bases. The methyl group is electron donor. Methyl amine, due to presence of electron donor methyl group, has higher electron density and is stronger base as compared to ammonia.
Take your CBSE board preparation to another level with AI based and rich media animation on Extramarks - The Learning App.
Features of Learning App