12th Class Chemistry Chapter 5 (The Helogens and Noble Gasses) Online Preparation

Question # 1

What is meant by available chlorine?

Ans 1: If excess of an acid is added to bleaching powder ,chlorine is given out.
The amount of chlorine thus set free is called available chlorine,The activity of bleaching powder is measured in terms of available chlorine,The average percentage of available chlorine in bleaching powder is 35-40%.

Question # 2

What are ferons and Teflons?

Ans 1: Ferons: Fluorine is used for the preparation of freons,Freons is the commercial name of low molecular mass fluoro chloro carbons.These are being used as the refrigerants and aerosol propellants.
Teflons:Fluorine is used for the preparation of Teflon,It is polymerized tetrafluoroethylene compound.It is valuable plastic which resists the action of oxidants,acid and alkalies.

Question # 3

Why HF is weaker acid that other halogen acid?

Ans 1: In water hydrogen halides give hydrofluoric ,hydrochloric ,hydrobromic and hydroiodic acid,The strength hydrogen halogen bond is very high in HF.The bond strength is reflected in the case of dissociation of hydrogen and halides,Hydrofluoric acid is week acid due to limited ionization,The other three acid are very strong acids,The acidic strength increase in order.

Question # 4

Write two use of bleaching powder?

Ans 1: Bleaching powder is used :
1. for the laboratory preparation of chlorine and oxygen.
2. for making unshrinkable wool.

Question # 5

Why oxidizing power of halogens decreases down the group?

Ans 1: Oxidizing power of halogens depends upon the following factors:
1. Energy of dissociation
2. Electron affinity of atoms
3. Hydration energy if ions
4. Heat of vapourization
While going down the group all above mentioned factors decreases, All the free halogens acts as oxidizing agents when they reacts with metals or non metals,On forming ionic compound with metals ,the hydrogens as gain of electrons and are converted to negative halide ions.

Question # 6

Compare halogen acids in their reducing properties?

Ans 1: HF,HCI,HBr and HI acts as reducing agents in the following order:
HF<HCI < HBr<HI

Question # 7

Define "disproportion reaction".

Ans 1: A reaction in which a species(molecule atom or ion )is simultaneously oxidized and reduced is called disproportion reaction.

Question # 8

Why iodine has metallic luster?

Ans 1: Due to big size of lodine outer electrons are excited by taking light and due to excitation and de-excitation gives metallic luster.

Question # 9

What are noble gasses?Why are they inert?

Ans 1: Elements of group VIII-A are called noble gases because these elements are colourless odourless monatomic gases which are chemically unreactive.
Noble gases are inert due to the completion of their outermost shell. These gases have complete electronic configuration and have filled duplet and octet.

Question # 10

On what factor oxidizing power of halogens depends upon?

Ans 1:
1. Energy of dissociation
2. Electrons affinity of atoms
3. Heat of vapourization

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2nd Year Chemistry Chapter 5 (The Helogens and Noble Gasses) Online Preparation

Online Short Questions For Chapter 5 "12th Class Chemistry Chapter 5 Short Questions Preparation "

Chemistry - 12th Class Chemistry Chapter 5 Short Questions Preparation

What is meant by available chlorine?

What are ferons and Teflons?

Why HF is weaker acid that other halogen acid?

Write two use of bleaching powder?

Why oxidizing power of halogens decreases down the group?

Compare halogen acids in their reducing properties?

Define "disproportion reaction".

Why iodine has metallic luster?

What are noble gasses?Why are they inert?

On what factor oxidizing power of halogens depends upon?

Prepare Complete Set Wise Questions For Chapter 5 "12th Class Chemistry Chapter 5 Short Questions Preparation "

Set 1

Set 2

Set 3

12th Class Chemistry Chapter 5 Short Questions Preparation - Set 1

What is meant by available chlorine?

What are ferons and Teflons?

Why HF is weaker acid that other halogen acid?

Write two use of bleaching powder?

Why oxidizing power of halogens decreases down the group?

Compare halogen acids in their reducing properties?

Define "disproportion reaction".

Why iodine has metallic luster?

What are noble gasses?Why are they inert?

On what factor oxidizing power of halogens depends upon?

12th Class Chemistry Chapter 5 Short Questions Preparation - Set 2

Why iodine has metallic luster?

HF is a weak acid while HCI is strong acid.Give reason.

Perchloric acid is considered as valuable analytical reagent.Why?

What are ferons and Teflons?

Write two application of noble gases?

Give two used of bromine?

Write two uses of halogen?

What is Halothane ?Write its formula.

How bleaching powder is prepared by Hasenclever method?

Arrange the following ions in order of increasing size F,CI,Br,I

12th Class Chemistry Chapter 5 Short Questions Preparation - Set 3

Describe factor of acidic strength of oxyacids of halogens?

Give two used of bromine?

Why oxidizing power of halogens decreases down the group?

Write any two use of Krypton?

Give one method of preparation and one use of I2O5?

HF is a weak acid while HCI is strong acid.Give reason.

What are noble gasses?Why are they inert?

Perchloric acid is considered as valuable analytical reagent.Why?

Give two application of Radon gas.

What are ferons and Teflons?

12th Class Chemistry Chapter 5 Preparation

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Give one method of preparation and one use of I₂O₅?