Reaction with Metals - general

• Many metals react with acids to form a salt and hydrogen gas.

• The general word equation is:

metal + acid a salt + hydrogen

• The salt will depend upon the metal and the acid used.

hydrogen+magnesium chloride

hydrochloricacid

+magnesium

•Hydrochloric acid gives Hydrochloric acid gives metal chloridesmetal chlorides•Sulphuric acid gives Sulphuric acid gives metal sulphatesmetal sulphates•Nitric acid gives Nitric acid gives metal nitratesmetal nitrates

•So, for example

Mg + acid

hydrogenLighted

spill

Oxygen in the air

Evidence of Reaction

Some of these reactions show bubbles being produced. These are bubbles of hydrogen gas. This proves that a reaction is taking place because a new substance is forming.

How do we test for hydrogen?

Zinc + hydrochloric + acid

• Use the general equation to finish of the word equations below

metal + acid a salt + hydrogen

iron + nitric acid +

calcium + sulphuric acid

+

iron nitrate

calcium sulphate

zinc chloride

hydrogen

hydrogen

hydrogen

magnesium + sulphuric acid

+magnesium sulphate

hydrogen

Activity

React with Metals – Metal Reactivity

• We can use the activity series of metals to predict how vigorously (if at all) a metal will react.

• The more reactive the metal, the more vigorous the reaction.

• The least reactive metals do not react at all.

• Which metal fits the description silver; potassium; iron

1. Explodes in acid

2. Bubbles slowly in warm acid

3. Doesn’t react

potassium

iron

silver

PotassiumsodiumcalciummagnesiumaluminiumzincIronLead(Hydrogen)(Hydrogen)coppersilvergold

Decreasing activity

Formula of salts

• Chemists often use formula equations to show not just what atoms are present but also how many.

• To do this we need to understand what the numbers in a formula represent. Here are some examples.

calcium nitrate

potassium sulphate

potassium nitrate

magnesium chloride

sodium chloride

Name of Salt

six Otwo None CaCa(NO3)2

four Oone Stwo KK2SO4

three Oone None KKNO3

two Clone MgMgCl2

one Clone NaNaCl

ContainsFormula

• How many of each type of atom does the formula of the salt represent?

Name of Salt Formula Contains

calcium chloride CaCl2 Ca Cl

sodium sulphate Na2SO4 Na S O

magnesium sulphate MgSO4 Mg S O

magnesium nitrate Mg(NO3)2 Mg N O

calcium sulphate CaSO4 Ca S O

one

two

one

one

one

two

one

one

two

one

four

four

six

four

Activity

Formula Equations:

• Step 1: Write down the word equation.• Step 2: Replace words with the chemical formula .

(You will be given or need to look up the formula at this stage.)

• Step 3: Check that there are equal numbers of each type of atom on both sides of the equation. If not, then balance the equation by using more than one.

• E.g. The reaction of magnesium with hydrochloric acid

Neither H nor Cl balance.Need 2 HClNeither H nor Cl balance.Need 2 HCl

magnesium + hydrochloric acid

magnesium chloride

+ hydrogen

Mg + HCl MgCl2 + H2

Mg + 22HCl MgCl2 + H2

• Can you finish off the equations below:– Step 1: Write down the word equation.– Step 2: Replace words with the

chemical formula. – Step 3: Balance the type of atom on both sides.

Already balances; No changeAlready balances; No change

magnesium + sulphuric acid

magnesium sulphate

+ hydrogen

Mg + H2SO4 MgSO4 + H2

Need 2 K on both sides Need 2 K on both sides

potassium + sulphuric acid

potassium sulphate

+ hydrogen

K + H2SO4 K2SO4 + H2

2K2K ++ HH22SOSO44 KK22SOSO44 ++ HH22

Activity

Metals with Hydrochloric Acid

2

hydrogen+magnesium chloride

hydrochloric acid

+magnesium

Mg + HCl MgCl2 + H2

No reactionhydrochloric acid

+copper

Cu + HCl - -

hydrogen+aluminium chloride

hydrochloric acid

+aluminium

Al + HCl AlCl3 + H2

hydrogen+calcium chloride

hydrochloric acid

+calcium

362 2

Ca + HCl CaCl2 + H22

2

Metals with sulphuric and nitric Acid

hydrogen+zinc sulphatesulphuric acid+zinc

Zn + H2SO4 ZnSO4 + H2

hydrogen+magnesium nitrate

nitric acid+magnesium

Mg + HNO3 Mg(NO3)2 + H2

hydrogen+iron nitratenitric acid+iron

Fe + HNO3 Fe(NO3)3 + H2

hydrogen+calcium sulphate

sulphuric acid

+calcium

362 2

Ca + H2SO4 CaSO4 + H2

2

Metal oxides and acids

Metal oxide + acid a salt + water

• Most metal oxides are not soluble.

• i.e. They are bases but not alkalis. This means they are often slower and may need heating to make them react

Acid

Oxide

water+copper sulphate

sulphuric acid

+Copper oxide

Metal oxides and acids

Metal oxide + acid a salt + water

water+zinc sulphate

sulphuric acid+zinc oxide

water+sodium chloride

hydrochloric acid

+sodium oxide

water+iron nitratenitric acid+iron oxide

ZnO + H2SO4 ZnSO4 + H2O

Na2O + 2HCl 2NaCl + H2O

Fe2O3 + 3HNO3 Fe(NO3)3 + 3H2O

Metal carbonates and acids

Metal carbonate + acid a salt + water + carbon dioxide

• When metal carbonates react with acids they fizz giving off carbon dioxide gas.

• Most metal carbonates are not very soluble and so reactions may be slow.

water+calcium chloride

hydrochloric acid

+calcium carbonate

carbon dioxide

+

Metal carbonates and acids

Metal carbonate + acid a salt + water + carbon dioxide

water+zinc sulphate

sulphuric acid

+zinc carbonate

ZnCO3 + H2SO4 ZnSO4 + H2O + CO2

+ carbon dioxide

water+sodium chloride

hydrochloric acid

+sodium carbonate

+ carbon dioxide

water+nickel nitrate

nitric acid+nickel carbonate

Na2CO3 + 2HCl 2NaCl + H2O + CO2

+ carbon dioxide

NiCO3 + 2HNO3 Ni(NO3)2 + H2O + CO2

2. Which of these is NOTNOT a typical property of metals?

A. conduct

B. strong

C. dense

D. brittle

3. What is the symbol for Gold?

A. Go

B. Au

C. Ag

D. au

4. Which of the following elements is not a metal?

A. copper

B. lead

C. lithium

D. neon

Which of these is a salt?

A) Sodium carbonate

B) Sodium chloride

C) Sodium hydroxide

D) Sodium

Which of these do all acids contain?

A) Hydrogen

B) Sulphur

C) Oxygen

D) Nitrogen

Which of these salts might be formed from nitric acid?

A) Potassium chloride

B) Sodium nitride

C) Aluminium sulphate

D) Calcium nitrate

Which of these metals might not react with hot dilute acid?

A) Sodium

B) Calcium

C) Silver

D) Iron

Which of these substances would not neutralise an acid?

A) Silver nitrate

B) Sodium carbonate

C) Calcium oxide

D) Magnesium hydroxide

What number must replace X to balance the equation?

Fe(OH)3 + X HCl 3H2O + FeCl3

A)1B)2C)3D)4

What number must replace X to balance the equation?

CaCO3 + X H2SO4 H2O + CaSO4 + CO2

A) 1B) 2C) 3D) 4