Halogens

Question 1

Who is the Russian scientist given credit for organising the periodic table?

Answer 1

Dimitri Mendelev. He organised them according to the atomic order and their properties.

Question 2

What is in Group 1 of the Periodic table (PT)

Answer 2

Alkali Metals. Lithium (Li), Sodium (Na),Potassium (K), Rubidium (Rb), Caesium (Cs),Francium (Fr).

Question 3

Why are they called Alkali Metals?

Answer 3

Because they turn water into an alkali

Question 4

Which is the most reactive in Group 1?

Answer 4

Francium - too dangerous to test in the classroom. Remember the video clip of the exploding bathtub?

Question 5

Which is the least reactive metal in Group 1?

Answer 5

Lithium.

Question 6

The Halogens are listed in which group of the Periodic table?

Answer 6

Group 7

Question 7

What does halogen mean?

Answer 7

…….means they form salts

Question 8

What happens to the reactivity of the metals as you go down the group?

Answer 8

They become less reactive as you go down the group. Flourine is the most reactive and Astatine the least reactive.

Question 9

What is the chemical symbols for the following:
Flourine (an extremely reactive gas), Chlorine (a poisonous gas),
Bromine (a poisonous liquid)
Iodine (a solid)

Answer 9

F2, Cl2, Br2, I2

Question 10

What does diatomic mean?

Answer 10

It means it has 2 (di) molecules.

Question 11

How does chlorine react with iron (wire wool)?

Answer 11

Reacts very quickly after a small amount of heating, burns vigorously with a bright yellow flame and Iron Chloride is produced.

Question 12

How does Bromine react with iron? (wire wool)?

Answer 12

It burns less vigorously than Chlorine but still with a bright yellow light. Iron bromide is formed and bromine gas escapes.

Question 13

How does Iodine react with iron (Wire wool)?

Answer 13

It burns after some time as it takes a lot of heating and the reaction is much slower. It still burns with a bright yellow light but less vigorously than Bromine. Iron iodide coats the wire wool (reddish brown in colour)

Question 14

What is formed when halogens react with metals?

Answer 14

Salts (of which there are many!!)

Question 15

Name one common salt produced by a halogen reaction.

Answer 15

NaCl…Soduim Chloride or common table salt (to put on your chips!!)

Question 16

Name some uses for Chlorine.

Answer 16

Used to make plastics (PVC) water treatment to stop disease, refrigerants (CFC’s - harmful to the ozone layer though!)

Question 17

Name some uses for Bromine.

Answer 17

It is extremely corrosive but is used in some drugs and pesticides.

Question 18

Name some uses for Iodine.

Answer 18

It is essential in our diet to control thyroid disease and is added to table salt and drinking water, used for the manufacture of medicines and dyes.

Question 19

What is a displacement reaction?

Answer 19

This means that the more reactive substance will DISPLACE the less reactive substance. e.g.
Flourine Sodium Bromide—>Sodium Flouride + Bromine
e.g.
Bromine+Sodium Flouride—-> No reaction (FLOURIDE MORE REACTIVE!!!!)

Question 20

Which is the most reactive - chlorine, bromine or iodine?

Answer 20

Chlorine

Question 21

Would flourine react with a solution of potassium chloride? Why?

Answer 21

Yes because flourine is the more reactive.

Question 22

Which properties of the halogens suggest they are non-metals?

Answer 22

They have low melting and boiling points and they have weak molecular bonds.

Question 23

What test could you do on iodine to prove it is a non-metal?

Answer 23

It would not conduct heat or electricity well so you could try passing a current through it and if it wont go through it is not a metal.

Question 24

How many molecules do the halogens have?

Answer 24

2, they are diatomic
e.g
Cl-Cl, Br-Br, Fl-Fl, I-I.