Microcosmic salt is from Chemistry Equilibrium

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

371.

Which of the following is not a Lewis base ?

  • NH3

  • H2O

  • AlCl3

  • None of these


372.

The solubility in water of a sparingly soluble salt AB2 is 1.0 × 10-5 mol L-1. Its solubility product number will be

  • 4 × 10-15

  • 4 × 10-10

  • 1 × 10-15

  • 1 × 10-10


373.

The correct order of increasing basic nature for the bases NH3, CH3NH2 and (CH3)2NH is

  • CH3NH2 < NH3 < (CH3)2NH

  • (CH3)2NH < NH3 < CH3NH2

  • NH3 < CH3NH< (CH3)2NH

  • CH3NH< (CH3)2NH < NH3


374.

The solubility of CaF2 in pure water is 2.3 ×10-6 mol dm-3. Its solubility product will be:

  • 4.8 ×10-18

  • 48.66 ×10-18

  • 4.9 ×10-11

  • 48.66 ×10-15


Advertisement
375.

Two moles of PCl5 were heated in a closed vessel of 2 L. At equilibrium 40% of PCl5 is  dissociated into PCl3 and Cl2.The,value of equilibrium constant is :

  • 0.53

  • 0.267

  • 2.63

  • 5.3


376.

What is the equilibrium expression for the reaction

P4 (s) + 5O2 (g)  P4O10 (s) ?

  • KcP4O10[P4][O2]5

  • KcP4O105[P4][O2]

  • Kc = [O2]5

  • Kc1[O2]5


377.

The pH value of 1/1000 N-KOH solution is :

  • 3

  • 10-11

  • 2

  • 11


378.

The temperature dependence of rate constant (k) of a chemical reaction is written in terms of Arrhenius equation, k = Ae-E*/ RT. Activation energy (E*) of the reaction can be calculated by plating

  • log k vs 1T

  • log k vs 1log T

  • k vs T

  • k vs 1log T


Advertisement
379.

The heats of combustion of carbon monoxide at constant pressure and at constant volume at 27°C will differ from one another by :

  • 27 cal

  • 54 cal

  • 300 cal

  • 600 cal


Advertisement

380.

Microcosmic salt is

  • Na4P2O7

  • Na(NH4)HPO4

  • Na(NH3)HPO4H2O

  • MgNH4PO4


B.

Na(NH4)HPO4

Microcosmic salt is Na(NH4)HPO4. It is white crystalline solid. It is separated by fractional crystallisation.

It is obtained when NH4Cl and Na2HPO4 are dissolved in hot water and cooled.

NH4Cl + Na2HPO4 → Na(NH4)HPO4 + NaCl

It is used for the detection of certain, basic radicals which forms coloured mixed phosphate with NaPO3.

Na(NH4)HPO4  NaPO3 + NH3 + H2O

NaPO3 + CoO → NaCo.PO4


Advertisement
Advertisement