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 determine the true statements regarding the production of quicklime (calcium oxide) from limestone (calcium carbonate), we can analyze the chemical reaction involved:

\[ \text{CaCO}_3 \ (\text{limestone}) \rightarrow \text{CO}_2 \ (\text{carbon dioxide}) + \text{CaO} \ (\text{quicklime}) \]

Based on this reaction, here are some true statements:

1. Limestone is composed of calcium carbonate (CaCO3): True, as this is the starting material for producing quicklime.

2. When heated, calcium carbonate breaks down into carbon dioxide and calcium oxide: True, this is exactly what happens when limestone is heated to high temperatures (around 1,500°C).

3. Calcium oxide is also known as quicklime: True, calcium oxide is commonly referred to as quicklime.

4. The reaction produces carbon dioxide gas: True, carbon dioxide (CO2) is a byproduct of the decomposition of calcium carbonate.

5. The process occurs at high temperatures in a kiln: True, the thermal decomposition of limestone takes place in a kiln where temperatures reach approximately 1,500°C.

Overall, these points summarize the key aspects of the chemical reaction involved in producing quicklime from limestone. If there are specific statements you want to evaluate for truthfulness, please provide those statements for a direct analysis.