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

Question # 1

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 # 2

What is bleaching powder?

Ans 1: Bleaching powder is yellowish white powder with strong smell of chlorine and is used to bleach different things.It has chlorine known as "available chlorine".

Question # 3

What is Halothane ?Write its formula.

Ans 1: Definition: Chemical compounds of halogens with ethylene is called halothane.
Formula: Fluorine is used to firm Teflon(-CF₂-CF₂-)_n.

Question # 4

Why the lattice energy of Fluorides is greater than Chlorides?

Ans 1: Due to small size of fluoride ions(f),there will be a better overlap of orbitals and consequently leads to shorter and stronger bonds with other elements.Ionic fluorides have higher lattice energies than the chlorides and the value is responsible for the insolubility of the fluorides in water.Due to low dissociation energy of fluorine molecule,it is highly reactive.The other halogens react slowly under similar conditions.The fluorides are,however more stable with respect to dissociation into elements.

Question # 5

Write four properties of hydrogen fluorides?

Ans 1:
1. HF is a colourless volatile liquid.
2. HF attacks glass and has found application as non aqueous solvent.
3. HF has meeting point as -83.8 degree,
4. HF has boiling point as 19.5 degree.

Question # 6

Write any two use of Krypton?

Ans 1: Krypton is used to fill fluorescent tubes and in flash lamps for high speed photography.

Question # 7

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 # 8

What is peculiar behaviour of Fluorine?

Ans 1: The halogen form a homologous series but fluorine differ from the other halogens in many respects which is due to :
1. Small in size of D atom and F ion,
2. High first ionization energy and electronegativity.
3. Low dissociation energy of F₂molecule as compared to CI₂and Br₂.
4. Restriction of the valence shell to an octet
5. Direst combination with inert gasses.

Question # 9

Give uses of iodine.

Ans 1: The major application of iodine are in pharmaceutical industry,It is used as disinfectants and germicides,Tincture of iodine and iodex are popular preparation of iodine.Diet with insufficient iodine ions leads to an enlargement of the thyroid,To ensure the present of iodine ion in the diet,sodium or potassium iodine is added to the common salt which is known as iodized salt.

Question # 10

Give two application of Radon gas.

Ans 1: 1.Radon is being radioactive is used in earthquake prediction.
2.Radon being radioactive is used in radiotherapy for cancer.

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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 are noble gasses?Why are they inert?

What is bleaching powder?

What is Halothane ?Write its formula.

Why the lattice energy of Fluorides is greater than Chlorides?

Write four properties of hydrogen fluorides?

Write any two use of Krypton?

What is meant by available chlorine?

What is peculiar behaviour of Fluorine?

Give uses of iodine.

Give two application of Radon gas.

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 are noble gasses?Why are they inert?

What is bleaching powder?

What is Halothane ?Write its formula.

Why the lattice energy of Fluorides is greater than Chlorides?

Write four properties of hydrogen fluorides?

Write any two use of Krypton?

What is meant by available chlorine?

What is peculiar behaviour of Fluorine?

Give uses of iodine.

Give two application of Radon gas.

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

Describe factor of acidic strength of oxyacids of halogens?

What are noble gasses?Why are they inert?

Define "disproportion reaction".

Write two use of bleaching powder?

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

What are the commercial use of halogens and their compounds?

Give reason that fluorine is gas ,iodine is solid?

What is Halothane ?Write its formula.

Why iodine has metallic luster?

What is meant by available chlorine?

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

Why iodine has metallic luster?

Write any two use of Krypton?

Give reason that fluorine is gas ,iodine is solid?

Why oxidizing power of F2is higher than other halogens?

Why HF is weaker acid that other halogen acid?

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

Give one method of preparation and one use of I2O5?

Write two use of bleaching powder?

Arrange the following oxyacids in increasing order of acid strength and oxidizing power ; HCIO4>HCIO2>HCIO

What is iodize salt?

12th Class Chemistry Chapter 5 Preparation

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Why oxidizing power of F₂is higher than other halogens?

Give one method of preparation and one use of I₂O₅?

Arrange the following oxyacids in increasing order of acid strength and oxidizing power ; HCIO₄>HCIO₂>HCIO