Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.
Advertisement

 Multiple Choice QuestionsMultiple Choice Questions

61.

A compound on burning in air produces three oxides. Out of these one oxide turns lime water milky, the second one turned anhydrous CuSO4 blue and third forms a solution of pH = 9. The compound is made up of

  • S, N and H

  • S, H and Na

  • S and N

  • S, C and H


62.

What is the conjugate base of OH ?

  • O2

  • H2O

  • O-

  • O2-


63.

The conjugate base of NH2- is

  • NH3

  • NH2-

  • NH4+

  • N3-


64.

In an amino acid, the carboxyl group ionises at pka1 = 2.34 and ammonium, ion at pka2 = 9.6. The isoelectric point of the amino acid is at pH

  • 5.97

  • 11.94

  • 2.34

  • 9.60


Advertisement
65.

The solubility product of Ag2CrO4 is 32 x 10-12.What is the concentration of CrO4- ions in that solution?

  • 2x 10-4 M

  • 16x 10-4 M

  • 8x 10-4 M

  • 8x 10-8 M


66.

Consider the water gas equilibrium reaction,

C (s) + H2O (g)  CO (g) + H2 (g)

Which of the following statements is true at equilibrium?

  • If the amount of C(s) is increased, less water would be formed

  • If the amount of C(s) is increased, more CO and H2 would be formed

  • If the pressure on the system is increased by halving the volume, more water would be formed

  • If the pressure on the system is increased by halving the volume, more CO and Hwould be formed


67.

The rate constant for forward reaction and backward reaction of hydrolysis of ester are 1.1 x10-2 and 1.5 x10-3 per minute respectively. Equilibrium constant for the reaction is

      CH3COOC2H5 + H2O  CH3COOH + C2H5OH

  • 33.7

  • 7.33

  • 5.33

  • 33.3


68.

The reaction

           2A(g) + B(g) 3C(g) + D(g)

is begun with the concentrations of A and B both at an initial value of 1.00 M. When equilibrium is reached, the concentration of D is measured and found to be 0.25 M. The value for the equilibrium constant for this reaction is given by the expression

  • [(0.75)3 (0.25)] ÷ [(1.00)2 (1.00)]

  • [(0.75)3 (0.25)] ÷ [(0.50)2 (0.75)]

  • [(0.75)3 (0.25)] ÷ [(0.50)2 (0.25)]

  • [(0.75)3 (0.25)] ÷ [(0.75)(0.25)]


Advertisement
Advertisement

69.

20 mL of 0.2 M NaOH is added to 50 mL of 0.2 M acetic acid. The pH of this solution after mixing is (Ka=1.8x 10°)

  • 4.5

  • 2.3

  • 3.8

  • 4


A.

4.5

              NaOH  +  CH3COOH    CH3COONa +  H2Ommnol  20 ×0.2      50 × 0.2                  0                      0added   =4                =10m mol afterreaction    0                   6                         4                         4[CH3COOH]=670                 :      [CH3COONa] =470pH= -log( 1.8 × 10-5) + log 4/706/70 = 4.56


Advertisement
70.

A vessel at 1000 K contains CO2 with a pressure of 0.5 atm. Some of the CO2 is converted into CO on the addition of graphite. The value of K if the total pressure at equilibrium is 0.8 atm, is

  • 1.8 atm

  • 3 atm

  • 0.3 atm

  • 0.18 atm


Advertisement