GUJARAT SECONDARY & HIGHER SECONDARY EDUCATION BOARD, 



GANDHINAGAR

EVALUATION BASED ON QUESTION BANK

QUESTION BANK – 2 (AUGUST - 2022)

INSTRUCTIONS:

1) In PART-A total 45 questions are given, choose any 9. (each of 1 mark)

2) In section A of Part - B total 15 questions are given, choose any 3. (each of 2 marks)

3) In section B of Part - B total 10 questions are given, choose any 2. (each of 3 marks)

4) In section C of Part - B total 05 questions are given, choose any 1. (each of 4 marks)



           PART-B  

                     SECTION-A

(1) Write the functions of salt bridge.

(2) Write Faraday’s laws of electrolysis.

(3) A solution of CuSO4 is electrolysed for 8 min 45 sec with a current of 5 A.

 What will be the mass of copper deposited at the cathode?

(4) Write the anodic and cathodic discharging reactions of lead storage cell.

(5) What is pseudo first order reaction? Give an example.

(6) Write two points of difference between molecularity and order of reaction. 



(7) A first order reaction takes 40 min for 30% decomposition. Calculate t1/2.

(8) List the factors affecting the rate of a chemical reaction.

(9) What is threshold energy?

(10) Explain froth-floatation method.

(11) Explain Mond carbonyl process.

(12) Explain leaching of gold and silver. 


XxXx


(13) Explain zone refining with diagram.

(14) Explain calcination.

(15) Why is the reduction of a metal oxide easier if the metal formed is in liquid

 state at the temperature of reduction?

                          

XXXX


                   SECTION B

(1) How much charge is required for the reduction of

 (i)1 mol of Al3+ to Al?

 (ii)1 mol of Cu2+

to Cu?

 (iii)1 mol of Mn𝑂4

− to Mn2+?

(2) The conductivity of 0.001028 mol L-1

acetic acid is 4.95 x 10-5 S cm-1

. Calculate

 the dissociation constant if ˄𝑚

0

for acetic acid is 390.5 S cm2 mol-1

.

(3) Explain standard hydrogen electrode (S.H.E.) with labeled diagram.

(4) What is corrosion? Write equations of reactions at anode and cathode for rusting

 of iron.

(5) Calculate the equilibrium constant of the reaction:

 Cu(s) + 2Ag+

(aq) → Cu2+

(aq) + 2Ag(s) (𝐸𝐶𝑢2+/𝐶𝑢

0

= 0.34 V, 𝐸𝐴𝑔+/𝐴𝑔

0

= 0.80 V)

(6) Derive the equation of rate constant and half life time for first order reaction.

(7) Derive the equation of rate constant and half life time for zero order reaction.

(8) From Arrhenius equation, derive the equation relating rate constants at two different temperatures and plot a graph of ℓ𝑛 K → 1

𝑇

.

(9) For a first order reaction, show that the time required for 99% completion is

 twice the time required for the completion of 90% of reaction.

(10) Explain Hall-Heroult process with diagram.


XXXXX


                       SECTION-C 

(1) Resistance of a conductivity cell filled with 0.1 mol L-1 KCl solution is 100 Ω.

 If the resistance of the same cell is 520 Ω when it is filled with 0.02 mol L-1

 KCl solution, then calculate the conductivity and molar conductivity of KCl

 solution. Conductivity of 0.1 mol L-1 KCl solution is 1.29 S m-1

.

(2) Write cell reactions occurring at electrodes in dry cell and fuel cell.

(3) Predict the products of electrolysis in each of the following.

 (a)An aqueous solution of AgNO3 with silver electrodes.

 (b)An aqueous solution of AgNO3 with platinum electrodes.

 (c) A dilute solution of H2SO4 with platinum electrodes.

 (d) An aqueous solution of CuCl2 with copper electrodes.

(4) The half-life for radioactive decay of 14C is 5730 years. An archaeological

 artifact containing wood had only 80% of the 14C found in a living tree.

 Estimate the age of the sample.

(5) The rate of a reaction quadruples when the temperature changes from 293 K to

 313 K. Calculate the energy of activation of the reaction assuming that it does

 not change with temperature. (R = 8.314 𝐽

𝐾−𝑚𝑜𝑙

) 






(1) Aqueous solution of which of the following compounds is the best conductor of

 electricity?

 (a)acetic acid, C2H4O2 (b)hydrochloric acid, HCl

 (c)ammonia, NH3 (d)Fructose, C6H12O6

(2) When 0.1 mol of MnO4

2-

is oxidized, the quantity of electricity required to

 completely oxidize MnO4

2-

 to 𝑀𝑛𝑂4

− is

 (a)96500 C (b)9650 C (c)2 x 96500 C (d)96.5 C

(3) Standard electrode potential of three metals X, Y and Z are -1.2 V, +0.5 V and

 – 3.0 V respectively, then reducing power of these metals will be

 (a) 𝑦 > 𝑧 > 𝑥 (b) 𝑦 > 𝑥 > 𝑧

 (c) 𝑧 > 𝑥 > 𝑦 (d) 𝑥 > 𝑦 > 𝑧 


XXXX


(4) How long should 3A current be passed to obtain 0.1 mol Cl2 gas through

 electrolysis of molten NaCl?

 (a)110 min (b)220 min (c)330 min (d)440 min

(5) What is the value of cell potential (Ecell) at equilibrium state?

 (a)positive (b)negative (c)infinite (d)zero

(6) Which of the following is used as anode in lead storage cell?

 (a)PbO2 coated plate (b)Pb plate (c)PbS plate (d) None of these



(7) What is the potential of hydrogen electrode, if the pH of electrolyte is 10?

 (a)0.59 V (b)0.00 V (c) -0.59 V (d) -0.059 V

(8) What will be the nature of the solution after electrolysis of aqueous solution of

 NaCl between Pt electrodes?

 (a)acidic (b)basic (c)Neutral (d)Cannot be determined

(9) Product of electrolytic cell does not depend on which of the following factors?

 (a)Concentration of the solution (b)Temperature

 (c)Nature of the solvent (d)Nature of the electrodes

(10) At 250C, if the cell potential of the given cell is 0.34 V, then calculate the

 standard reduction potential of copper.

 Given: Pt / H2(g)(1 atm) / H+

(aq)(1 M) // Cu2+

(aq)(1 M) /Cu(s)

 (a)3.4 V (b) -3.4 V (c) -0.34 V (d)0.34 V

(11) Resistance of cell containing 1 N CH3COOH solution is 250 Ω. Its cell

 constant is 1.15 cm-1

. Then the equivalent conductivity of 1 N CH3COOH is

 _______ Ω-1

cm2

eq-1

.

 (a)4.6 (b)0.46 (c)0.046 (d)46.0

(12) ˄𝑚

0



(CH3COOH) is equal to ________

 (a) ˄𝑚(C𝐻3COOH)

0 + ˄𝑚(C𝐻3COOK)

0 + ˄𝑚(C𝐻3COONa)

0

 (b) ˄𝑚(HCl)

0 + ˄𝑚(C𝐻3COONa)

0

- ˄𝑚(NaCl)

0

 (c) ˄𝑚(KCl)

0 + ˄𝑚(C𝐻3COOK)

0

- ˄𝑚(HCl)

0

 (d) ˄𝑚(KCl)

0 + ˄𝑚(C𝐻3COONa)

0

- ˄𝑚(NaCl)

0

(13) An electrochemical cell can behave like an electrolytic cell when ________ .

 (a)Ecell < Eext (b) Ecell > Eext (c) Ecell = Eext (d) Ecell = 0

(14) The cell constant of a conductivity cell ________________.

 (a)changes with change of electrolyte

 (b)changes with change of concentration of electrolyte

 (c)changes with temperature of electrolyte

 (d)remains constant for a cell

(15) The quantity of charge required to obtain one mol of aluminium from Al2O3 is 



 


 (a)1 F (b)2 F (c)3 F (d)6 F

(16) The difference between the electrode potential of two electrodes when no

 current is drawn through the cell is called _________.

 (a)cell potential (b)cell voltage

 (c)cell emf (d)potential difference

(17) The formula of rust when iron gets oxidized by atmospheric oxygen is

 (a)Fe2O3 (b) Fe2O3∙ 𝑥𝐻2𝑂 (c)Fe3O4 (d) Fe3O4∙ 𝑥𝐻2𝑂



(18) The role of a catalyst is to change ____________.

 (a)Gibb’s energy of reaction (b)enthalpy of reaction

 (c)activation energy of reaction (d)equilibrium constant

(19) For the reaction, A + B → Product, rate = K [A]3

[B]0

. If concentration of A is

 doubled and the concentration of B is halved, then the rate of reaction will

 increase by

 (a)4 times (b)8 times (c)2 times (d)10 times

(20) A first order reaction is 50% completed in 1.26 x 1014 s. How much time

 would it take for 100% completion?

 (a)1.26 x 1015 s (b)2.52 x 1014 s (c)2.52 x 1028 s (d)infinite

(21) If for a reaction, rate constant K = 175 L2 mol-2

s

-1

, then the order of the

 reaction is __________.

 (a)1 (b)2 (c)3 (d)0

(22) What is the formula to find half life of zero order reaction?

 (a)0.693

𝐾

(b)[𝑅]0

2𝐾

(c) 2𝐾

[𝑅]0

(d) 𝐾

[𝑅]0

(23) What is the unit of rate constant for pseudo first order reaction?

 (a)L mol-1

s

-1

(b)s

-1

(c)mol L-1

s

-1

(d)L

2 mol-2

s

-1

(24) Which of the following statements is incorrect about Arrhenius equation?

 (a)It gives relation between K and T

 (b)T increases as K increases and A decreases

 (c)Ea increases as K increases

 (d)If Ea = 0, then K =A

(25) If the rate of reaction is equal to rate constant, then the order of reaction is

 (a)2 (b)3 (c)0 (d)1

(26) For a reaction 3A → 2B, the rate of reaction + 𝑑[𝐵]

𝑑𝑡

is equal to _______.

 (a) -

3

2

𝑑[𝐴]

𝑑𝑡

(b) -

2

3

𝑑[𝐴]

𝑑𝑡

(c) -

1

3

𝑑[𝐴]

𝑑𝑡

(d) +2

𝑑[𝐴]

𝑑𝑡

(27) What is the molecularity of a reaction 2NO + O2 → 2NO2?

 (a)1 (b)2 (c)3 (d)4

(28) If the graph log K → 1

𝑇

is plotted, a straight line is obtained. Then what will be

 the value of a slope of that graph?

(a) –

𝐸𝑎

𝑅

(b) –

2.303

𝐸𝑎∙𝑅

(c) –

1

2.303 𝑅

(d) –

𝐸𝑎

2.303 𝑅

(29) If temperature is increased from 300 K to 310 K, the rate of reaction increases

 by 2.5 times. If rate constant is K at 300 K temperature, then what will be the

 rate constant at 310 K?

 (a)2.5 K (b)3 K (c)2 K (d) K 


(30) A first order reaction takes 60 minutes for 60% completion. What time will it

 take for 50% completion?

 (a)40 min (b)45 min (c)50 min (d)60 min

(31) Half life of a reaction is found to be inversely proportional to the cube of its

 initial concentration. The order of reaction is ________.

 (a)2 (b)3 (c)4 (d)5

(32) For a chemical reaction, _______ can never be a fraction.

 (a)order (b)Half-life (c)molecularity (d)rate constant

(33) In the equation for collision theory, rate = P ∙ ZAB 𝑒

−

𝐸𝑎

𝑅 𝑇 , What does P indicate?

 (a)Pressure (b)Collison frequency

 (c)Arrhenius factor (d)Probability factor

(34) Order of a reaction is determined by

 (a)temperature (b)pressure

 (c)molecularity (d)reaction mechanism

(35) Which of the following ore can be concentrated by froth floatation method?



 (a)magnetite (b)siderite (c)sphalerite (d)malachite

(36) Which process is used for purification of nickel?

 (a)Van-Arkel (b)Chromatography (c)Mond (d)Zone refining

(37) The molecular formula of cryolite is _________.

 (a)Fe3O4 (b)NaAlO2 (c)Na3AlF6 (d)Al2(SO4)3∙6H2O

(38) Copper matte is a mixture of _________.

 (a)Cu2S + FeO (b)Cu2O + Cu2S

 (c)Cu2S + CuS (d)Cu2S + FeS

(39) The method for oxidation of pyrite ore by heating is known as ________.

 (a)smelting (b)roasting (c)calcination (d)bessemerisation

(40) Which of the following methods is used in electrolysis of alumina?

 (a)Van-Arkel (b)Bessemerisation

 (c)Hall-Herault (d)Bayer’s process

(41) Which principle is involved in chromatographic separation?

 (a)Adsorption (b)Hydration (c)decomposition (d)Precipitation

(42) Which of the following is an ore of zinc?

 (a)Bauxite (b)Haematite (c)Copper pyrite (d)Calamine



(43) Temperature range plays an important role in the extraction of which metal?

 (a)Cu (b)Fe (c)Zn (d)Na

(44) Free energy change of oxidation-reduction reaction should be ______.

 (a)>0 (b)<0 (c)0 (d)1

(45) Which impurity is not present in bauxite?

 (a)oxides of calcium (b)oxides of titanium

 (c)oxides of iron (d)oxides of silicon


ગુજરાતી માધ્યમ 



રસાયણ વિજ્ઞાન એકમ કસોટી પેપર સંપૂર્ણ સોલ્યુશન