Group 1

Question 1

What are the products of a reaction between group 1 metals and water?

Answer 1

A solution of metal hydroxide and hydrogen gas is formed.

2X(s) + H2O(l) 2XOH(aq) + H2(g)

Question 2

Describe the reaction between group 1 metals and water

Answer 2

All of the group 1 metals react vigorously or even explosively with cold water. In each case, a solution of the metal hydroxide is produced together with hydrogen gas.

Question 3

Describe the reaction of lithium (group 1) with water

Answer 3

Lithium’s density is only about half that of water so it floats on the surface, gently fizzing and giving off hydrogen. It gradually reacts and disappears, forming a colourless solution of lithium hydroxide.

Question 4

Describe the reaction of sodium (group 1) with water

Answer 4

Sodium floats on the surface, but enough heat is given off to melt the sodium and it melts almost at once to form a small silvery ball that dashes around the surface. Dissolves to give a colourless solution of sodium hydroxide. May form orange flame.

Question 5

Describe the reaction of potassium (group 1) with water

Answer 5

Potassium behaves rather like sodium except that the reaction is faster and enough heat is given off to set light to the hydrogen. The normal hydrogen flame is contaminated by potassium compounds and so is coloured lilac (a faintly bluish pink).

Question 6

Describe the reaction of ribidium (group 1) with water

Answer 6

Rubidium is denser than water and so sinks. It reacts violently and immediately, with everything spitting out of the container again. Rubidium hydroxide solution and hydrogen are formed.

Question 7

Describe the reaction of caesium (group 1) with water

Answer 7

Caesium explodes on contact with water, quite possibly shattering the container. Caesium hydroxide and hydrogen are formed

Question 8

Describe the reactivity with water down group 1

Answer 8

The Group 1 metals become more reactive towards water as you go down the Group.