C6

Question 1

What group are the alkali metals, and what are their properties?

Answer 1

• group 1
• react readily with group 7: in water to form hydroxides, and in oxygen to for oxides

Properties:
- soft (lithium hardest)
- low boiling points (lithium highest)
- increasing reactivity as you move down the group

Question 2

What are the products of a reaction between lithium and water?

Answer 2

Lithium hydroxide and hydrogen

Question 3

What would be observed when lithium reacts with water?

Answer 3

• slow reaction
• bubbles of hydrogen
• doesn’t melt

Question 4

What would be observed when sodium reacts with water?

Answer 4

• faster reaction
• floats on surface (less dense than water)
• bubbles of hydrogen cause it to float around
• melts

Question 5

What would be observed when potassium reacts with water?

Answer 5

• more violent
• hydrogen bubbles cause it to whizz around on the water’s surface
• melts into a shiny ball
• burns with a lilac flame

Question 6

What group are the halogens in, and what are their properties?

Answer 6

• group 7

Properties:
- boiling and melting points increase as you go down the group (this is because molecules are bigger - there are more intermolecular forces to overcome)
- reactivity decreases as you go down the group
- forms an acidic solution when hydrogen halide reacts with water

Question 7

What is the colour and state of chlorine at room temperature, and what is its chemical test?

Answer 7

• pale green gas
• use damp litmus paper places into a test tube of gas - if chlorine is present, the litmus paper will turn red then white due to the chlorine bleaching

Question 8

What is the colour and state of bromine at room temperature?

Answer 8

Red-brown liquid

Question 9

What is the colour and state of iodine at room temperature?

Answer 9

Black solid

Question 10

Are halogen diatomic?

Answer 10

Yes they sure are

Question 11

What is produces when a halogen reacts with a metal?

Answer 11

Metal halide salt

Question 12

What properties of helium makes it suitable for use in ballons?

Answer 12

• less dense than air
• does not burn

Question 13

Why is argon used to fill electric light bulbs?

Answer 13

• very chemically inert (wont react when bulb gets hot
• non-flammable

Question 14

Why is argon used for welding?

Answer 14

• provides inert welding atmosphere
• argon is more dense than air so keeps air away from the metal

Question 15

What are the trends in group 0?

Answer 15

• boiling point increases as you go down
• density increases as you go down