On dissolving moderate amount of sodium metal in liquid NH3 at lo

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

431.

The pair whose both species are used in antiacid medicinal preparation is

  • NaHCO3 and Mg(OH)2

  • Na2CO3 and Ca(HCO3)2

  • Ca(HCO3)2 and Mg(OH)2

  • Ca(OH)and NaHCO3.


432.

Which of the following is a false statement ?

  • Fluorine is more electronegative than chlorine

  • Nitrogen has greater IE1 than oxygen

  • Lithium is amphoteric

  • Chlorine is an oxidising agent


433.

Which of the following is a use of alum ?

  • Making explosives

  • Bleaching clothes

  • Water softening

  • All of the above


434.

The pair of amphoteric hydroxides is

  • Al(OH)3, LiOH

  • Be(OH)2, Mg(OH)2

  • B(OH)3, Be(OH)2

  • Be(OH)2, Zn(OH)2


Advertisement
435.

Which of the following is only acidic nature?

  • Be(OH)2

  • Mg(OH)2

  • B(OH)3

  • Al(OH)3


436.

The molecular formula of 'salt petre' is :

  • KNO3

  • NaNO3

  • NaCl

  • Na2SO4


Advertisement

437.

On dissolving moderate amount of sodium metal in liquid NH3 at low temperature, which one of the following does not occur?

  • Blue coloured solution is obtained.

  • Na+ ions are formed in the solution.

  • Liquid NH3 becomes good conductor of electricity

  • Liquid ammonia remains diamagnetic


D.

Liquid ammonia remains diamagnetic

When moderate amount of sodium metal in liquid NH3 is dissolved, liquid ammonia remains dimagnetic. This is because the alkali metals dissolve in liquid ammonia without evolution of hydrogen. The colour of the dilute solution is blue and are paramagnetic in nature.

M → M+ (in liquid ammonia) + e- (ammoniated)

M + (x + y) NH3 → [M(NH3)x]+ + e- (NH3)y


Advertisement
438.

Which of the following reaction produces hydrogen ?

  • Mg + H2O

  • H2S2O8 + H2O

  • BaO2 + HCl

  • Na2O2 + 2HCl


Advertisement
439.

Assertion: Mg is not present in enamel of human teeth.

Reason : Mg is an essential element for biological functions of human.

  • If both assertion and reason are true and reason is the correct explanation of assertion

  • If both assertion and reason are true but reason is not the correct explanation of assertion

  • If assertion is true but reason is false

  • If both assertion and reason are false.


440.

Match the flame colours of the alkaline earth metal salts in the Bunsen burner.
A. Calcium p. Brick red
B. Strontium q. Apple green
C. Barium r. Crimson

  • A - p; B - r; C - q

  • A - r; B - p; C - q

  • A - q; B - r; C - p

  • A - p; B - q; C - r


Advertisement