The production of concrete requires cement. Almost all cement is made by heating clay minerals and limestone together in a kiln, a type of oven that can reach high temperatures.

Question

The limestone contains calcium carbonate
(CaCO3)
. When limestone is heated to about 1,500°C, it breaks into carbon dioxide gas
(CO2)
and calcium oxide
(CaO)
, or quicklime. The chemical reaction below shows how quicklime is made.
Ca
C
O
3
C
O
2
+
Ca
O
Select the true statements.

Answer 1

To evaluate the true and false statements regarding the production of cement and the reaction involving limestone (calcium carbonate), it’s important to consider the information provided.

The chemical reaction for the thermal decomposition of calcium carbonate (limestone) is as follows:

\[ \text{CaCO}_3 \ (s) \rightarrow \text{CaO} \ (s) + \text{CO}_2 \ (g) \]

Here are some statements that could be considered true or false concerning the information provided:

1. Limestone is composed of calcium carbonate.

   • True. Limestone primarily consists of calcium carbonate (CaCO3).

2. Heating limestone produces calcium oxide and carbon dioxide.

   • True. The heating process decomposes calcium carbonate into calcium oxide (CaO) and carbon dioxide (CO2).

3. The reaction occurs at temperatures above 2,000°C.

   • False. The decomposition of calcium carbonate occurs at about 1,500°C, but not necessarily above 2,000°C.

4. Calcium oxide is also known as quicklime.

   • True. Calcium oxide (CaO) is commonly referred to as quicklime.

5. Carbon dioxide is produced as a solid in this reaction.

   • False. Carbon dioxide (CO2) is produced as a gas in this reaction.

6. Cement can be produced without the use of limestone.

   • False. Cement production typically requires limestone as a primary raw material.

If you have specific statements you would like to analyze, please provide them, and I can confirm if they are true or false based on the information provided!