What substance is decomposed into CO2 and CaO in the blast furnace?1 markCokeLime stoneCarbonCarbon dioxide

The substance that is decomposed into CO2 and CaO in the blast furnace is Limestone. Here's the step by step process:

1. Limestone (Calcium Carbonate - CaCO3) is used in a blast furnace as a source of calcium.

2. When it is heated, it undergoes thermal decomposition. This is a reaction where a single substance breaks down into two or more simpler substances when heated.

3. The heat in the furnace causes the Limestone to decompose into Carbon Dioxide (CO2) and Calcium Oxide (CaO).

4. The chemical reaction can be represented as follows: CaCO3(s) → CaO(s) + CO2(g)

So, the correct answer is Limestone.