C1- Rocks and building materials

Question 1

How is cement made?

Answer 1

By heating a mixture of limestone and clay in a kiln

Question 2

Name the four substances used to make concrete.

Answer 2

Cement,sand, water,aggregate or crushed rock/ stones.

Question 3

What is meant by thermal decomposition of a compound?

Answer 3

BreakBreaking down of a compound buy heating

Question 4

Name the products formed when calcium carbonate is heated strongly.

Answer 4

Calcium oxide and carbon dioxide

Question 5

Write a word equation for the reaction of calcium carbonate with water

Answer 5

Calcium oxide+ water -> calcium hydroxide

Question 6

Limewater goes cloudy when mixed with carbon dioxide. Explain why using a equation in your answer.

Answer 6

Calcium carbonate is formed and is insoluble, calcium hydroxide + carbon dioxide-> calcium carbonate + water

Question 7

Explain, as fully as you can why acids damage limestone.

Answer 7

Acids react with calcium carbonate producing carbon dioxide and a salt. The salt dissolves in water and so the amount of limestone decreases or it is worn away

Question 8

Farmer spreads calcium hydroxide on fields with acidic soils. Explain why, naming the type of reaction that take place and the property of calcium hydroxide on which this reactions depends.

Answer 8

Calcium hydroxide reacts with acids,because calcium hydroxide is an alkali,and the reaction is neutralisation ( the pH of the soil increases, which is better for growing crops)

Question 9

Balance this symbol equation:

K2CO3 + HCI -> H2O + CO2

Answer 9

K2CO3 + 2HCI->2KCI+ H2O + CO2

Question 10

Which of these is the formula for the main compound in limestone?
CaCI2,CaCO3,CaSo4,Ca(OH)2

Answer 10

CaCO3