Halogen

Question 1

Uses of chlorine

Answer 1

Making bleach
Production of some plastics as PVC
Production of bromine
Production of hydrochloric acid
In purification of drinkable water (sterilising agent

Question 2

Uses of fluorine

Answer 2

Used in water supply
And toothpaste to prevent the decay of the enamel of the tooth

Question 3

Uses of iOdine

Answer 3

Used as Antiseptic

Question 4

Why reactivity decreases from up to down along the group?

Answer 4

As the atoms get larger,the outermost shell gets further from the nucleus,attraction between the nucleus and electrons in the outer shell gets weaker so electrons is less easy to gain electrons

Question 5

General properties of halogen?

Answer 5

They are diatomic
Bromine is very Voltaile so easy to turn to gas
Halogen are strong oxidising agent as its has high tendency to gain electrons
Outermost energy level of halogens contains 7 electrons
Iodine is dark grey solid when wormed turns into a purple vapour
Halogen are very active elements

Question 6

What is the most active elements in group 7

Answer 6

Fluorine

Question 7

Color of fluorine when gas,aqueous,ions

Answer 7

Yellow, colourless, colourless

Question 8

Colour of chlorine when gas, aqueous,ions

Answer 8

Green,yellow, colourless

Question 9

Colour of bromine when gas, liquid, aqueous,ions

Answer 9

Orange,brown,orange or red, colourless

Question 10

Colour of iodine when gas,solid, aqueous,ion

Answer 10

Purple
Dark grey
Brown
Colourless

Question 11

Colour of astatine when solid and ion

Answer 11

Black, colorless

Question 12

Write equation of hydrogen chloride when dissolved in water with symbol

Answer 12

Hcl(g)+H2O(l)=hcl(aq)

Question 13

Write chemical equation when chlorine passed through Aqueous solution of potassium bromide with symbol and what change of colour

Answer 13

Cl2(g)+2kbr(aq)=2kcl(aw)+br2(aq)
Colorless to orange

Question 14

Give me example when halogen react with hydrogen gas where hydrogen halide formed

Answer 14

H2(g)+f2(g)=2hf(g)

Question 15

Why hydrogen chloride is gas at room temperature

Answer 15

Because the molecules bondeed by weak inter molecular force

Question 16

Is reactivity decreases or increase down group

Answer 16

Decrease

Question 17

Is mp and bp decrease or increase down group

Answer 17

Increase

Question 18

Write solution of chlorine in water with symbol

Answer 18

Cl2(g)+H20(l)=HCl(aq)+hocl(aq)

Question 19

HCl(g) is —-compound

Answer 19

Covalent

Question 20

Hcl (aq) is simple —-structure

Answer 20

Ionic

Question 21

What will happen when we dissolve HCl(g) in water and why

Answer 21

Give acidic solution by HCl(aq) and turns purple litmus paper to red, conduct electricity and react with active metal due to its ionisation into h+ and cl-

Question 22

Test for Chlorine gas

Answer 22

Gas turn damp blue litmus paper into red then bleaches

Question 23

What will happen when HCl(g) dissolve in methylbenzene why

Answer 23

Dissolve as a simple molecule and not ionized,give neutral solution which doesn’t conduct electricity,dont Change colour of litmus paper as it has no free moving ion