Double Award Science: CCEA Chemistry

Reaction of Potassium with water

Potassium is silver in appearance and is stored under oil in a laboratory. Observations when potassium reacts with water include; the metal will form a sphere shape and float on the surface of the water, The sphere of metal will move rapidly across the surface of the water, heat is relesed along with bubbles of gas being produced. The potassium will burn with a lilac flame and eventually will dissolve.

Reaction of Sodium with water

Sodium is a silver metal which is stored under oil in a laboratory. When sodium reacts with water the following observations can be made;The sodium melts, forming a sphere of molten metal which rapidly moves across the surface of the water/floats, Heat is released along with bubbles of gas being produced. The sodium may eventually burn with a yellow flame.

Reaction of Calcium with water

Calcium is a silver metal which is stored under oil in a laboratory. When reacted with water, calcium sinks initially but will continually rise to the top of the surface. Bubbles of gas are produced along with heat released. A grey, gritty, powdery solid forms at the bottom(Calcium Hydroxide.)

In all cases the universal indicator turned blue showing an alkali was present(metal hydroxide)

These metals must never be reacted with acid as the reaction produced would be too violent.

When a metal such as Magnesium reacts with steam (gaseous form of water) a Metal Oxide is produced.

Reactions with Steam

Magnesium - Very bright white light. A white powder will remain (Magnesium Oxide)

Aluminium - small pieces wil react after the oxide layer is removed. A white powder is formed.

Zinc - Glows as steam is passed over, producing a yellow powder. Yellow powder cools to form a white powder.

Iron - Heated until it glows red before the steam is passed over. Reacts to form a black solid.

Reactions when left in Air

Calcium - Burns with a brick red flame

Magnesium - Burns with a bright white flame leaving a white ash

Aluminium - Powdered aluminium burns with white sparks leaving a white solid

Zinc - Burns leaving a yellow solid which cools to form a white solid

Iron - Wool or filings burn with white sparks forming a black solid

Copper - A black layer of copper oxide will form without heating

A Displacement Reaction is one in which a more reactive element displaces a less reactive element from its compound

Reactions with Copper Sulfate

Magnesium - Bubbles of gas created, Exothermic reaction, Pink solid formed, Magnesium displaces copper from the solution

Zinc - Sinks to the bottom, Exothermic reaction, Colour change Blue…