Topic 3 - GROUPS 1 + 7

Question 1

What is produced when a group 1 metal reacts with water?

Answer 1

Group 1 metals react vigorously with water to produce an alkaline metal hydroxide + hydrogen gas.

metal + water —> metal hydroxide + hydrogen

Question 2

Give 3 examples of group 1 metals

Answer 2

Potassium, sodium and lithium

Question 3

What is formed when litium reacts with water?

Answer 3

Lithium + water –> lithium hydroxide + hydrogen

2Li + H2O —> 2LiOH + H2

Question 4

What are some observations of reaction of water with POTASSIUM , SODIUM OR LITHIUM? (similarities)

Answer 4

1. Fizzing (bubbles of hydrogen gas)
2. metal floats + move aroud surface
3. metal dissapears

Question 5

Describe reaction of lithium with water

Answer 5

• reaction slower than with sodium
• Bubbles of hydrogen gas
• lithium has high melting point so heat isnt produced so quickly therefore lithium DOESNT MELT.

Question 6

Describe reaction of Sodium with water

Answer 6

2Na + H2o —> 2NaOH + H2

• Bubbles of hydrogen gas
• melts into shiny ball + dashes across surface
• melts because has low melting point + a lot of heat made in reaction
• floats on water because less dense

WHITE TRAIL OF SODIUM HYDROXIDE PRODUCED: which dissolves in water producing highly alkaline solution.

Question 7

Describe reaction of Potassium with water

Answer 7

2K + H2O –> 2KOH + H2

• Bubbles of hydrogen gas
• Reacts more strongly than sodium
• melts into tiny ball + dashes across surface
• enough heat produced so potassium burns with
  lilac-coloured flame.

Question 8

What happens to the reactivity of GROUP 1 METALS as you go down the group?

Answer 8

As you go down group 1 , reactivity increases

Question 9

Reaction of Lithium with air

Answer 9

Burns with red flame

Question 10

Reaction of Sodium with air

Answer 10

Burns with yellow/orange flame

Question 11

Reaction of Potassium with air

Answer 11

Burns with lilac-coloured flame

Question 12

What are halogens?

Answer 12

Group 7 NON-METALS that are POISONOUS

Question 13

Give examples of halogens

Answer 13

Fluorine, Chlorine, Bromine, Iodine + Astatine

Question 14

Why are halogens diatomic?

Answer 14

They form molecules of 2 atoms

Question 15

What is the PHYSICAL STATE, COLOUR + COLOUR IN SOLUTION of FLUORINE?

Answer 15

Gas
Yellow
-

Question 16

What is the PHYSICAL STATE, COLOUR + COLOUR IN SOLUTION of CHLORINE?

Answer 16

Gas
Pale green
Green - blue

Question 17

What is the PHYSICAL STATE, COLOUR + COLOUR IN SOLUTION of BROMINE?

Answer 17

Liquid
Red-brown (rapidly evaporates + forms brown gas)
Orange

Question 18

What is the PHYSICAL STATE, COLOUR + COLOUR IN SOLUTION of IODINE?

Answer 18

Solid
Black (sublimes to form purple gas)
Dark brown

Question 19

What is the state of Chlorine, Bromine + Iodine at room temp. (20ºC)?

Answer 19

Chlorine: gas
Bromine: liquid
Iodine: solid

Question 20

What happens to the melting + boiling points of halogens as you go down the group?

Answer 20

Melting + Boiling Points of halogens INCREASES as you go down the group.

• fluorine at top: lowest m+b. p
• astatine at bottom: highest m+b. p

Question 21

Why do Rubidium, Caesium + Francium react more vigorously than other Group 1 metals?

Answer 21

Because reactivity increases down the group

• they are at the bottom of group 1

Question 22

Describe the reaction of Rubidium with water

Answer 22

• EXPLODES with sparks + rubidium hydroxide produced

Question 23

Describe the reaction of Caesium with water

Answer 23

• Violent explosion + rapid production of heat + hydrogen

Question 24

Describe the reaction of Francium with water

Answer 24

TOO REACTIVE!!!!!

Question 25

What happens to the colour of the halogens?

Answer 25

Become DARKER down the group

• fluorine on top: lighter colour (yellow)
• Astatine on bottom: darker colour (black)

Question 26

What happens to state of halogens?

Answer 26

Become more HARD + SET down the group

• fluorine at top: gas
• Astatine at bottom: solid