Metals and Oxygen

• Many metals will react with oxygen from the air to produce a metal oxide.

• Often, they will need to be heated before they can react

Metals and Water/Steam

• Very reactive metals like sodium will react with cold water to produce a metal hydroxide and hydrogen gas. An example of this is = sodium + water → sodium hydroxide + hydrogen 2Na(s) + 2H2

• Other metals like magnesium only react with steam, and produce a metal oxide and hydrogen. An example of this is = Mg(s) +H2O(g) → MgO(s) +H2(g)

• Magnesium can be reacted with steam using a setup which uses a glass tube, with a magnesium ribbon and a mineral wool soaked in water inside, which is clamped and heated with a Bunsen burner.

State Symbols

• Symbol equations have letters in brackets after each substance.

• These tell you the state of matter of each substance, and are called state symbols: (s) = solid, (l) = liquid, (g) = gas, (aq) = dissolved in water

• H2O(s) is ice,

• H2O(l) is water

• H2O(g) is steam

• NaCl(aq) is sodium chloride (table salt) dissolved in water.

Metals and Acids

• If a metal reacts with an acid, it produces a salt and hydrogen gas.

• All acid compounds have hydrogen in them.

• When the hydrogen is replaced by a metal, the compound is called a salt.

For example, sulfuric acid has the formula H2 SO4 so copper sulfate has the formula CuSO4 – it is a salt because the copper has taken the place of the hydrogen in sulfuric acid.

• The three main acids are hydrochloric acid, sulfuric acid, and nitric acid.

• Metals can react with all of these acids to produce a salt and hydrogen gas.

• Examples-

copper + hydrochloric acid → copper chloride + hydrogen

iron + sulfuric acid → iron sulfate + hydrogen

magnesium + nitric acid → magnesium nitrate + hydrogen

Testing for Hydrogen gas

• The gas produced when reacting a metal and a salt can be collected in an upturned test tube, and a test is performed to check that the gas is hydrogen.

• Insert a lit splint into the upturned test tube – if the gas is hydrogen, there will be a squeaky ‘pop’ sound.

Reactivity

• A displacement reaction occurs when a more reactive element takes the place of a less reactive element in a compound.

• In metals, this means that the more reactive metal will become a compound, and the less reactive one an element.

The Reactivity Series