Reactions of Acids - Metals Worksheet

Acids react with metals to produce a salt and hydrogen gas. This can be shown in a word equation:

Acid + Metal Salt + Hydrogen

Not all metals react with acids - unreactive metals such as gold and platinum do not react with acids, but metals such as magnesium and zinc react very vigorously with acids. Some metals, such as sodium, are so reactive that they should never be placed into acid.

When a small piece of magnesium metal is added to hydrochloric acid, lots of bubbles of hydrogen gas are produced and the conical flask becomes hot. The hydrogen gas can be collected and tested.

Reaction producing gas

Hydrogen gas is explosive and when a small volume is collected and ignited a 'squeaky' pop is produced. This is the test for hydrogen gas, but this should only be performed with small volumes as large volumes will result in large explosions.

Match the column on the right, which shows some chemical tests, to the column on the left showing the gases they test for.

Column A	Column B
Hydrogen	burns with a pop
Oxygen	relights a glowing splint
Carbon dioxide	turns limewater cloudy white

Shown here is a picture of a Zeppelin airship which was an early form of air travel.

Zeppelin airship

These airships were filled with hydrogen gas.

Which of the reasons below would be a safety concern when hydrogen is used to fill the balloons?

hydrogen is very heavy

hydrogen is very flammable

hydrogen is corrosive

Hydrogen gas can be used to power cars. The hydrogen gas reacts with oxygen to produce water.

Which of the following is the correct equation for this reaction? Choose from A, B, C or D as your answer.

A Hydrogen + Oxygen Hydrogen

B Water + Oxygen Hydrogen

C Hydrogen + Oxygen Water

D Hydrogen + Water Oxygen

A

B

C

D

Magnesium metal reacts with sulfuric acid to produce magnesium sulfate and hydrogen gas.

Use this information to complete the word equation shown below:

A + sulfuric acid B + C gas

Column A	Column B
A	hydrogen
B	magnesium
C	magnesium sulfate

Which of the following pollution problems could have the effect of weakening metal structures by increasing their rate of corrosion?

noise pollution

acid rain

global warming

Which of the substances below would you expect to have the most vigorous reaction with zinc metal?

nitric acid

water

vinegar

Some sports cars have alloy wheels that contain the metal magnesium. Magnesium alloy wheels are lighter than ordinary wheels.

Magnesium alloy wheel

Which of the following should not be used to clean magnesium alloy wheels?

soap and water

'Super' wheel cleaner (pH 1)

'Science Special' wheel cleaner (pH 6)

'Shiny Wheels' wheel cleaner (pH 7)

ANSWERS

Question 1

Match the column on the right, which shows some chemical tests, to the column on the left showing the gases they test for.

CORRECT ANSWER

Column A	Column B
Hydrogen	burns with a pop
Oxygen	relights a glowing splint
Carbon dioxide	turns limewater cloudy white

EDDIE SAYS

It is important to nail these basic gas tests: you'll come across them so often, it's probably not an issue, but they are used so much that getting to know them is vital.

ANSWERS

Question 2

Shown here is a picture of a Zeppelin airship which was an early form of air travel.

Zeppelin airship

These airships were filled with hydrogen gas.

Which of the reasons below would be a safety concern when hydrogen is used to fill the balloons?

CORRECT ANSWER

hydrogen is very flammable

EDDIE SAYS

The Hindenburg disaster in 1937 was a dramatic illustration of just how flammable hydrogen gas is. Run a search on the web to see what happened.

ANSWERS

Question 3

Hydrogen gas can be used to power cars. The hydrogen gas reacts with oxygen to produce water.

Which of the following is the correct equation for this reaction? Choose from A, B, C or D as your answer.

A Hydrogen + Oxygen Hydrogen

B Water + Oxygen Hydrogen

C Hydrogen + Oxygen Water

D Hydrogen + Water Oxygen

CORRECT ANSWER

C

EDDIE SAYS

This seems pretty straightforward but, key point here, reading the question carefully provides the answer! Remember, it's hydrogen reacting with oxygen. Go from there.

ANSWERS

Question 4

Magnesium metal reacts with sulfuric acid to produce magnesium sulfate and hydrogen gas.

Use this information to complete the word equation shown below:

A + sulfuric acid B + C gas

CORRECT ANSWER

Column A	Column B
A	magnesium
B	magnesium sulfate
C	hydrogen

EDDIE SAYS

Word equations list the reactants and products of a chemical reaction, so make sure you've got the reactants sorted first. Then the products flow from that. Be organised and it becomes a whole lot easier!

ANSWERS

Question 5

Which of the following metals would you not expect to react with an acid?

EDDIE SAYS

Unreactive metals such as gold, silver and platinum won't react with most acidic substances. That's why they tend to stay shiny and are popular for jewellery.

ANSWERS

Question 6

Which of the following pollution problems could have the effect of weakening metal structures by increasing their rate of corrosion?

CORRECT ANSWER

acid rain

EDDIE SAYS

Acid rain increases the rate of corrosion of metal structures such as bridges if they are not well protected from the elements. As most bridges will contain a good proportion of steel (mainly iron), the acids in the rain speed up the rusting process.

ANSWERS

Question 7

Which of the substances below would you expect to have the most vigorous reaction with zinc metal?

CORRECT ANSWER

nitric acid

EDDIE SAYS

Strong acids like nitric acid react very vigorously with metals. Weak acids such as vinegar would react with the zinc but the reaction would be a lot slower.

ANSWERS

Question 8

Some sports cars have alloy wheels that contain the metal magnesium. Magnesium alloy wheels are lighter than ordinary wheels.

Magnesium alloy wheel

Which of the following should not be used to clean magnesium alloy wheels?

CORRECT ANSWER

'Super' wheel cleaner (pH 1)

EDDIE SAYS

The lower the pH number the more acidic the substance is. Some alloy wheel cleaners are highly acidic and may react with the magnesium in the alloy wheels causing them to corrode prematurely.