Chemistry

The p-Block Elements.

Question:

Write a balanced equation for the hydrolytic reaction of PC is in heavy water.

Answer:

ncert-solutions-for-class-12-chemistry-the-p-block-elements-6

previuos
next

The p-Block Elements.

Q 1.

Name three oxoacids of nitrogen. Write the disproportionation reaction of that oxoacid of nitrogen in which nitrogen is in +3 oxidation state.

Q 2.

How is O3 estimated quantitatively?

Q 3.

Discuss the trends in chemical reactivity of group 15 elements.

Q 4.

Match the items of Column I and Column II and mark the correct option.
ncert-exemplar-problems-class-12-chemistry-p-block-elements-49
ncert-exemplar-problems-class-12-chemistry-p-block-elements-50

Q 5.

Mention three areas in which H2SO4 plays an important role.

Q 6.

Explain why inspite of nearly the same electronegativity, nitrogen forms hydrogen bonding while chlorine does not.

Q 7.

In the preparation of H2S06 by contact process, why is S03 not absorbed directly in water to form H2S04?

Q 8.

Explain why does the stability of oxoacids of chlorine increase in the order given below:
HClO < HClO2 < HClO3 < HClO4

Q 9.

PCl5 reacts with finely divided silver on heating and a white silver salt is obtained, which dissolves on adding excess aqueous NH3 solution. Write the reactions involved to explain what happens.

Q 10.

 Why is BiH3 the strongest reducing agent amongst all the hydrides of group 15 elements? (C.B.S.E. 2013)

Q 11.

Which aerosols deplete ozone?

Q 12.

Write a balanced equation for the hydrolytic reaction of PC is in heavy water.

Q 13.

Write main differences between the properties of white phosphorus and red phosphorus.

Q 14.

Why are halogens strong oxidising agents?

Q 15.

Write a balanced chemical equation, for the reaction showing catalytic oxidation of NH3 by atmospheric oxygen.

Q 16.

PH3 forms bubbles when passed slowly in water but NH3 dissolves. Explain.

Q 17.

Phosphorus forms a number of oxoacids. Out of these oxoacids phosphinic acid has strong reducing property. Write its structure and also write a reaction showing its reducing behaviour.

Q 18.

Assertion (A): HNO3 makes from passive.
Reason (R): HNO3 forms a protective layer of ferric nitrate on the surface of iron.

Q 19.

 What is the covalence of nitrogen in N2O5 ?

Q 20.

 What happens when PCl5 is heated?

Q 21.

Give two examples to show the anomalous behaviour of fluorine.

Q 22.

Write the reactions of F2 and Cl2 with water.

Q 23.

Why is N2 less reactive at room temperature?

Q 24.

How is O3 estimated quantitatively?

Q 25.

How is nitrogen prepared in the laboratory? Write the chemical equations of the reactions . involved.

Q 26.

Why does nitrogen show catenation properties less than phosphorus?

Q 27.

Give the disproportionation reaction of H3 P03 .

Q 28.

Why is dioxygen a gas but sulphur a solid?

Q 29.

Write the reactions of F2 and Cl2 with water.

Q 30.

List the uses of neoirand argon gases.

Q 31.

On heating ammonium dichromate and barium azide separately we get
(a) N2 in both cases
(b) N2 with ammonium dichromate and NO with barium azide
(c) N2O  with ammonium dichromate and N2 with barium azide
(d) N2O with ammonium dichromate and N2O with barium azide

Q 32.

Which of the following is correct for P4 molecule of white phosphorus?
(a) It has 6 lone pairs of electrons (b) It has six P – P single bonds
(c) It has three P – P single bonds (d) It has four lone pairs of electrons,

Q 33.

Which of the following statements are correct?
(a) Among halogens, radius ratio between iodine and fluorine is maximum.
(b) Leaving F – F bond, all halogens have weaker X – X bond than X – X’ bond in interhalogens.
(c) Among interhalogen compounds maximum number of atoms ate present in iodine fluoride.
(d) Interhalogen compounds are more reactive than halogen compounds.

Q 34.

Which of the following statements are correct?
(a) S – S bond is present in H2S2O6.
(b) In peroxosulphuric acid (H2SO5) sulphur is in +6 oxidation state.
(c) Iron powder along with Al2O3 and K2O is used as a catalyst in the preparation of NH3 by Haber's process
(d) Change in enthalpy is positive for the preparation of SO3 by catalytic oxidation of SO2.

Q 35.

Nitric acid forms an oxide of nitrogen on reaction with P4O10. Write the reaction involved. Also write the resonating structures of the oxide of nitrogen formed.

Q 36.

Match the formulas of oxides given in Column I with the type of oxide given in Column II and mark the correct option.
ncert-exemplar-problems-class-12-chemistry-p-block-elements-47

Q 37.

Assertion (A): HI cannot be prepared by the reaction of KI with concentrated H2SO4.
Reason (R): HI has lowest H – X bond strength among halogen acids.

Q 38.

On heating compound (A) gives a gas (B) which is a constituent of air. This gas when treated with 3 mol of hydrogen (H2   ) in the presence of a catalyst gives another gas (C) which is basic in nature. Gas C on further oxidation in moist condition gives a compound (D) which is a part of acid rain. Identify compounds (A) to (D) and also give necessary equations of all the steps involved. –

Q 39.

How does ammonia react with a solution of Cu2+?

Q 40.

Why is bond angle in PH+4 ion higher than in PH3 ? (Pb. Board 2009)

Q 41.

 Which of the following does not react with oxygen directly? Zn, Ti, Pt, Fe

Q 42.

Write the conditions to maximise the yield of H2SO4 by Contact process.

Q 43.

Give the reason for bleaching action of Cl2.

Q 44.

Why is ICI more reactive than l2?

Q 45.

Why is helium used in diving apparatus?

Q 46.

Why has it been difficult to study the chemistry of radon?

Q 47.

 How is nitrogen prepared in the laboratory? Write the chemical equations of the reactions . involved.

Q 48.

Illustrate how copper metal can give different products on reaction with HN03.

Q 49.

Give the resonating structures of N02 and N2O5.

Q 50.

The HNH angle value is higher than HPH, H AsH and HSbH angles. Why?
(Hint: Can be explained on the basis of sp3 hybridisation in NH3 and only s-p bonding , between hydrogen and other elements of the group).