Oxidation Reduction Reaction

Q.

When Copper powder is heated in a china dish the surface of the copper powder becomes coated with a black colour substance. Why has this black-coloured substance formed? What is that black substance? Write the chemical equation of the reaction.

Q.

Which of the following is an example of combination reaction between two compounds?

1. Formation of sulphur dioxide

2. Formation of water

3. Formation of limestone

4. Formation of sulphur trioxide

Q. A chemical reaction where two compounds react, and the cation and the anion of the two reactants switch places, forming two new compounds or products is called as a ___ reaction.

Q.

The reaction in which hydrogen is added to substance and oxygen is removed from substance, is called __ reaction.

Q. A chemical reaction where two compounds react, and the cation and the anion of the two reactants switch places, forming two new compounds or products is called as a ___ reaction.

Q. Metals like lithium and calcium are ________ to metal hydrides (oxidised/reduced)

Q.

Select the correct answer from the choices A, B, C, and D which are given. Write only the letter corresponding to the correct answer.

Potassium chlorate (+ heat) ⇢ Potassium chloride + oxygen ( $2{\mathrm{KClO}}_3\stackrel{∆}{\to }2\mathrm{KCl}+3{\mathrm{O}}_2$) is an example of

1. Double decomposition reaction

2. Simple displacement reaction

3. Synthesis or direct combination reaction

4. Decomposition reaction

Q.

What happens when $\mathrm{Phosphorous}$ burns in $\mathrm{Oxygen}$ ?