Fsc part 2 online preparation for chemistry chapter 4 (Group VA and VIA Elements)

Question # 1

Name three allotropic forms of phosphorous>

Ans 1: Phosphorus can exist in at least six different solid allotropic forms.But here mentioned only three.
Ans 2: i) White phosphorus (P₄)
Ans 3: ii) Red phosphorus (macromolecule of P₄)
Ans 4: iii) Black phosphorus (high temperature heating of red P)

Question # 2

How does HNO₃act as an oxidizing agent?

Ans 1: It acts as a strong oxidizing agent due to the ease with which it is decomposed.
2HNO_3(aq)---------->H₂O + 2NO₂(g) +[O]_(g)

Question # 3

Justify that H₂SO₄is a king of chemicals?

Ans 1: H₂SO₄has many applications in daily life,laboratories,industries etc.What's common to petrol,fertilizers,cars and soap?They,like a lot of other things require sulfuric acid to be made.That's why sulfuric acid is called the king of chemicals.

Question # 4

How does nitrogen differ from other elements of its group?Give four points.

Ans 1: i)Nitrogen is diatomic gas and occurs in free state while other members tetra atomic solids and occur in combines state.
Ans 2: ii) Nitrogen does not show allotropy while other do except bismuth.
Ans 3: iii) Nitrogen shows +1,+2,+3,+4,+5,-1,-2,-3 oxidation states,while other elements don't show the variety of oxidation states.
Ans 4: iv) Nitrogen is poor conductor of heat electricity and give acidic oxides except phosphorus while other member are not.

Question # 5

Write any four important uses of H₂SO₄?

Ans 1: i) It is used in manufacturing of fertilizers like ammonium sulphate and calcium superphosphate.
Ans 2: ii) It is used in refining of petroleum to remove nitrogen and sulphur compounds.
Ans 3: iii) It is used in manufacturing of HCI,H₃PO₄,HNO₃and sulphates.
Ans 4: iv) It is used in electrical batteries and storage cells.

Question # 6

Why SO₃is dissolved in H₂SO₄and not in water?

Ans 1: SO₃is not directly dissolved in water,since absorption is incomplete and mist of SO₃and H₂SO₄fills the factory,which causes great causes great inconvenience the workers.Therefor,SO₃is absorbed in concentrated H₂SO₄and Oleum(H₂S₂O₇) formed can be converted to sulphuric acid of any strength by mixing adequate quantities of water.

Question # 7

How H₃PO₄is prepared on large scale?

Ans 1: It is prepared by dissolving phosphorus trioxide in cold water.
P₂O₃+ 3H₂O------->H₃PO₃
Ans 2: It is also obtained by the hdrolysis of phosphorus trichloride.
PCI₃+ 3H₂O--------->H₃PO₃+ 3HCI

Question # 8

How does HNO₃act as an oxidizing agent?

Ans 1: It acts as a strong oxidizing agent due to the ease with which it is decomposed.
2HNO_3(aq)---------->H₂O + 2NO₂(g) +[O]_(g)

Question # 9

Give definition of allotropy. Write allotropes of phosphorus.

Ans 1: Definition:When an elements exist in different crystalline forms.These crystalline forms are called allotropic forms and this phenomenon is called allotropy.
Ans 2: Allotropic forms of phosphorous:Phosphorus can exist in at least six different solid allotropic forms.But here mentioned only three.
Ans 3: i) Write phosphorus (P₄)
ii) Red phosphorus (macromolecule of P₄)
iii) Black phosphorus (high temperature heating of red P)

Question # 10

Write the formulas of (a) Phosphorite (b) Chile saltpeter.

Ans 1: a) Phosphorite: Ca₃(PO₄)2
b) Chile saltpeter: NaNO₃

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Fsc part 2 online preparation for chemistry chapter 4 (Group VA and VIA Elements)

Online Short Questions For Chapter 4 "12th Class Chemistry Chapter 4 Short Questions Preparation "

Chemistry - 12th Class Chemistry Chapter 4 Short Questions Preparation

Name three allotropic forms of phosphorous>

How does HNO3act as an oxidizing agent?

Justify that H2SO4is a king of chemicals?

How does nitrogen differ from other elements of its group?Give four points.

Write any four important uses of H2SO4?

Why SO3is dissolved in H2SO4and not in water?

How H3PO4is prepared on large scale?

How does HNO3act as an oxidizing agent?

Give definition of allotropy. Write allotropes of phosphorus.

Write the formulas of (a) Phosphorite (b) Chile saltpeter.

Prepare Complete Set Wise Questions For Chapter 4 "12th Class Chemistry Chapter 4 Short Questions Preparation "

Set 1

12th Class Chemistry Chapter 4 Short Questions Preparation - Set 1

Name three allotropic forms of phosphorous>

How does HNO3act as an oxidizing agent?

Justify that H2SO4is a king of chemicals?

How does nitrogen differ from other elements of its group?Give four points.

Write any four important uses of H2SO4?

Why SO3is dissolved in H2SO4and not in water?

How H3PO4is prepared on large scale?

How does HNO3act as an oxidizing agent?

Give definition of allotropy. Write allotropes of phosphorus.

Write the formulas of (a) Phosphorite (b) Chile saltpeter.

12th Class Chemistry Chapter 4 Preparation

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How does HNO₃act as an oxidizing agent?

Justify that H₂SO₄is a king of chemicals?

Write any four important uses of H₂SO₄?

Why SO₃is dissolved in H₂SO₄and not in water?

How H₃PO₄is prepared on large scale?

How does HNO₃act as an oxidizing agent?

How does HNO₃act as an oxidizing agent?

Justify that H₂SO₄is a king of chemicals?

Write any four important uses of H₂SO₄?

Why SO₃is dissolved in H₂SO₄and not in water?

How H₃PO₄is prepared on large scale?

How does HNO₃act as an oxidizing agent?