C1.2 - Rocks and building materials

Question 1

What is limestone mainly made out of?

Answer 1

Calcium carbonate.

Question 2

What is limestone used for?

Answer 2

• Building materials
• Calcium Oxide
• Cement

Question 3

How do you make concrete?

Answer 3

Cement mixed with sand, aggregate and water.

Question 4

What is the equation for calcium carbonate decomposition?

Answer 4

CaCO₃ → CaO + CO₂

Calcium carbonate → Calcium Oxide + Carbon dioxide

Question 5

What does thermal decomposition mean?

Answer 5

Breaking down by heating.

Question 6

What is produced when metal carbonates decompose, when they are heated strongly enough?

Answer 6

Metal oxide + carbon dioxide

Question 7

What carbonates can a Bunsen burner not decompose?

Answer 7

Sodium carbonate

Potassium carbonate

Question 8

What is produced when carbonates react with an acid?

Answer 8

Salt (of carbonate) + water + carbon dioxide

Question 9

What does hydrochloric acid + zinc carbonate react to form? Give the chemical formula too.

Answer 9

Hydrochloric acid + zinc carbonate → zinc chloride + carbon dioxide + water

2HCl(aq) + ZnCO₃(s) → ZnCl₂(aq) + CO₂(g) + H₂O(l)

Question 10

What does carbon dioxide do to limewater?

Answer 10

Turns it cloudy.

Question 11

Describe the 4 steps of the limestone cycle.

Answer 11

1. Thermal decomposition of calcium carbonate. Carbon dioxide is given off here. PRODUCT: calcium oxide.
2. Add water to calcium oxide. PRODUCT: calcium hydroxide.
3. Add more water and filter. PRODUCT: calcium hydroxide solution (limewater).
4. Add carbon dioxide. PRODUCTS: calcium carbonate + water.

Question 12

Is calcium hydroxide an acid or alkali and where can it be used?

Answer 12

• Alkali
• Used to neutralize acids.
• Used by farmers to neutralize acidic soils.
• Used in industry to neutralize acidic gases.

Question 13

What are the three word equations in the limestone cycle?

Answer 13

Calcium carbonate → calcium oxide + carbon dioxide
Calcium oxide + water → calcium hydroxide
Calcium hydroxide + carbon dioxide → calcium carbonate + water

Question 14

What are the three chemical equations in the limestone cycle?

Answer 14

CaCO₃ → CaO + CO₂
CaO + H₂O → Ca(OH)₂
Ca(OH)₂ + CO₂ → CaO + H₂O

Question 15

How do you make cement?

Answer 15

Limestone is mixed with clay and heated strongly in a kiln. Product is ground up to make a fine powder.

Question 16

How do you make mortar and what is it used for?

Answer 16

Cement is mixed with sand and water.

This is used to hold bricks together in buildings.

Question 17

Name 3 advantages of limestone quarrying.

Answer 17

• More employment opportunities for young people.
• More customers and trade for local businesses.
• Improved roads.

Question 18

Name 3 disadvantages of limestone quarrying.

Answer 18

• Dust and noise.
• More traffic.
• Loss of habitats for wildlife.