GCSE SCIENCE CHEMISTRY HIGH SCHOOL - The Reactivity of Dilute Acid with Metals

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Reaction with Dilute Acid.

Potassium, sodium, lithium and calcium
all react violently with dilute sulfuric acid and dilute hydrochloric acid.
It is dangerous to put these metals into an acid.
The reaction is similar to the reaction with water,
forming the metal salt (either sulfate or chloride) plus H_2(g).

For example

sodium + hydrochloric acid sodium chloride + hydrogen.
2Na_(s) + 2HCl_(aq) 2NaCl_(aq) + H_2(g)

Magnesium, aluminium, zinc, iron, tin and lead react safely with dilute acid.
Magnesium is the fastest and lead is the slowest of the six.

magnesium + sulfuric acid magnesium sulfate + hydrogen.
Mg_(s) + H₂SO₄_(aq) MgSO₄_(aq) + H_2(g)

magnesium + hydrochloric acid magnesium chloride + hydrogen.
Mg_(s) + 2HCl_(aq) MgCl₂_(aq) + H_2(g) (see rate)

aluminium + hydrochloric acid aluminium chloride + hydrogen.
2Al_(s) + 6HCl_(aq) 2AlCl₃_(aq) + 3H_2(g)

zinc + sulfuric acid zinc sulfate + hydrogen.
Zn_(s) + H₂SO₄_(aq) ZnSO₄_(aq) + H_2(g)

iron + hydrochloric acid iron(II) chloride + hydrogen.
Fe_(s) + 2HCl_(aq) FeCl₂_(aq) + H_2(g)

tin + hydrochloric acid tin(II) chloride + hydrogen.
Sn_(s) + 2HCl_(aq) SnCl₂_(aq) + H_2(g)

lead + sulfuric acid lead sulfate + hydrogen.
Pb_(s) + H₂SO₄_(aq) PbSO₄_(s) + H_2(g)

The reaction of zinc with sulfuric acid is often used
to make a small amount of hydrogen in the laboratory - see moles.
The reaction is slow at room temperature
but its rate can be increased by the addition of a little copper(II) sulphate.
Zinc displaces copper metal, which acts as a catalyst.

Metals below hydrogen in the reactivity series
(copper, silver, gold and platinum) will not react with dilute acid.
They cannot displace hydrogen from the non-metal anion.
See displacement reactions (next page).

Headings Reactivity Series Search Questions

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