What is the colour of ferrous sulphate crystals? How does this colour change after heating?

Solid calcium oxide was taken in a container and water was added slowly to it.

State two observations made in the experiment.

Solid calcium oxide was taken in a container and water was added slowly to it.

Write the name and the chemical formula of the product.

Name the substance oxidised and the substance reduced, and also identify the oxidising agent and reducing agent in the following reactions:

$3{\mathrm{MnO}}_2 + 4\mathrm{Al} \to 3\mathrm{Mn} + 2{\mathrm{Al}}_2{\mathrm{O}}_3$

Name the substance oxidised and the substance reduced, and also identify the oxidising agent and reducing agent in the following reaction:

${\mathrm{Fe}}_2{\mathrm{O}}_3+\mathrm{CO}\to 2\mathrm{Fe}+3{\mathrm{CO}}_2$

Name the substance oxidised and the substance reduced, and also identify the oxidising agent and reducing agent in the following reaction:

${\mathrm{SO}}_2 + 2{\mathrm{H}}_2\mathrm{S} \to 3\mathrm{S} +2{\mathrm{H}}_2\mathrm{O}$