Chemistry

The p-Block Elements.

Question:

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

Answer:

Pt being a noble metal does not react with oxygen directly. In contrast, Zn, Ti and Fe are active metals and hence they react with oxygen directly to form their oxides.

previuos
next

The p-Block Elements.

Q 1.

Write balanced equations for the following:
(i) NaCl is heated witlrsulphuric acid in the presence of MnO2
(ii) Chlorine gas is passed into a solution of Nal in water.

Q 2.

Discuss the general characteristics of Group 15 elements with reference to their electronic configuration, oxidation state, atomic size, ionisation enthalpy and electronegativity.

Q 3.

 Why is N2 less reactive at room temperature?

Q 4.

List the important sources of sulphur.

Q 5.

Comment on the nature of two S-O bonds formed in S02 molecule. Are the two S-O bonds in this molecule equal ?

Q 6.

What is the basicity of H3PO4?

Q 7.

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 8.

How is O3 estimated quantitatively?

Q 9.

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).

Q 10.

How is ammonia manufactured industrially?

Q 11.

Out of H2O and H2S, which one has higher bond angle and why?

Q 12.

White phosphorus reacts with chlorine and the product hydrolysis in the presence of water. Calculate the mass of HCl obtained by the hydrolysis of the product formed by the reaction of 62 g of white phosphorus with chlorine in the presence of water.

Q 13.

 What happens when PCl5 is heated?

Q 14.

 Discuss the general characteristics of Group 15 elements with reference to their electronic configuration, oxidation state, atomic size, ionisation enthalpy and electronegativity.

Q 15.

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

Q 16.

Give the resonating structures of N02 and N2O5.

Q 17.

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).

Q 18.

Give the disproportionation reaction of H3 P03 .

Q 19.

Which of the following statements are correct?
(a) All three N – O bond lengths in HNO3 are equal.
(b) All P – Cl bond lengths in PCl5 molecule in gaseous state are equal.
(c) P4  molecule in white phosphorus have angular strain therefore white phosphorus is very reactive.
(d) PCl5 is ionic in solid state in which cation is tetrahedral and anion is octahedral.

Q 20.

Which of the following orders are correct as per the properties mentioned against each?
ncert-exemplar-problems-class-12-chemistry-p-block-elements-23

Q 21.

Which of the following statements are true?
(a) Only type of interactions between particles of noble gases are due to weak dispersion forces.
(b) Ionisation enthalpy of.molecular oxygen is very close to that of xenon.
(c) Hydrolysis of XeF6 is a redox reaction.
(d) Xenon fluorides are not reactive.

Q 22.

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

Q 23.

Explain why ozone is thermodynamically less stable than oxygen.

Q 24.

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

Q 25.

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

Q 26.

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

Q 27.

Explain why NH3 is basic while BiH3 is only feebly basic.

Q 28.

 Write balanced equations for the following:
(i) NaCl is heated witlrsulphuric acid in the presence of MnO2
(ii) Chlorine gas is passed into a solution of Nal in water.

Q 29.

 How are XeOand XeOF4prepared?

Q 30.

Mention the conditions required to maximise the yield of ammonia.

Q 31.

Nitrogen exists as diatomic molecule and phosphorus as P4. Why?

Q 32.

Can PCl5 act as an oxidising as well as a reducing agent Justify.

Q 33.

Describe the manufacture of H2SO4 by contact process?

Q 34.

Write the reactions of F2 and Cl2 with water.

Q 35.

Why is nitric oxide paramagnetic in gaseous state but the solid obtained on cooling is diamagnetic?

Q 36.

In the ring test of NO3 ion.Fe2+ion reduces nitrate ion to nitric oxide, which combines with Fe2+  (aq.) ion to form brown complex. Write the reactions involved in the formation of brown ring.

Q 37.

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 38.

Assertion (A): SF6 cannot be hydrolysed but SF4 can be.
Reason (R): Six F atoms in SF6 prevent the attack of H2O on sulphur atom of SF6.

Q 39.

Mention the conditions required to maximise the yield of ammonia.

Q 40.

How does ammonia react with a solution of Cu2+?

Q 41.

 What is the covalence of nitrogen in N2O5 ?

Q 42.

 Write the order of thermal stability of the – hydrides of Group 16 elements.

Q 43.

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

Q 44.

What happens when sulp’hur dioxide is passed through an aqueous solution of Fe(III) salt?

Q 45.

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

Q 46.

Why is Ka2 « Ka1 for H2SO4 in water?

Q 47.

Give two examples to show the anomalous behaviour of fluorine.

Q 48.

Sea is the greatest source of some halogens. Comment.

Q 49.

Why does NH3 form hydrogen bond but PH3 does not?

Q 50.

How is ammonia manufactured industrially?