Metals and Reactivity Series Topic

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1. Describe how potassium, sodium, lithium and calcium react with water

These alkali metals (K, Na, Li) all react

with cold water(H2O)

to form a soluble alkali metal hydroxide and hydrogen gas, the test for

hydrogen is a lighted splint and you will hear a pop!. All three metals are

soft and has a lower density than water and so they float.

ALL

THE METALS ARE STORED IN OIL TO STOP THEM FROM OXIDISING!

How

Does Sodium react with water?

When you freshly cut the surface it is

shiny, when the surface is exposed to air it gets coated in a dull white

layer(sodium oxide).

Reaction

with water :

Sodium melts and forms into a floating

ball of metal which fizzes as it moves over the surface of the water, also a

yellow flame appears, the pH of the solution formed is 12-14, the gas produced

is hydrogen and the name of the solution produced is Sodium

Hydroxide.

How

Does

Lithium react

with water?

When you

freshly cut the surface it is shiny, when the surface is exposed to air it gets

coated in a dark grey coating(lithium oxide).

Reaction

with water :

Lithium is less reactive than sodium and

it does not melt but it does float around the water and fizzes, it reacts

quickly with cold water giving off hydrogen gas. The pH of the solution formed

is 12-14, the name of the gas produced is hydrogen and the name of the solution formed is lithium hydroxide.

How

Does Potassium

react

with water?

When you

freshly cut the surface it is shiny, when the surface is exposed to air it very

quickly oxidizes.

Reaction

with water :

Potassium is more reactive than sodium

and lithium. It floats, melts to a round ball, reacts vigorously and fizzes, it

burns with lilac flame as it gives off hydrogen gas. But large amounts of

potassium is dangerous and can explode when it comes into contact with water.The

pH of the solution formed is 12-14,the name of the gas produced is hydrogen and the name of the solution formed is potassium hydroxide.

Equations:

Sodium + Water = Sodium Hydroxide + Hydrogen

2Na(s) + 2H2O(l) 2NaOH(aq) + H2(g)

Lithium + Water = Lithium Hydroxide + Hydrogen

2Li(s) + 2H2O(l) 2LiOH(aq) + H2(g)

Potassium + Water = Potassium Hydroxide + Hydrogen

2K(s) + 2H2O(l) 2KOH(aq) + H2(g)

How Does Calcium react with water?

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