In the above image, an experiment is performed where the china dish containing about 1.2 g of copper powder is heated. We observe that the surface of the copper powder becomes black.
1. What is the type of the chemical reaction in the above experiment?
(i) Reduction
(ii) Decomposition
(iii) Addition
(iv) Oxidation
2. State true or false: The copper powder becomes black because oxygen is added to copper and copper oxide is formed.
(i) TRUE
(ii) FALSE
3. If hydrogen gas is passed over this heated material (CuO), the black coating on the surface turns
(i) White
(ii) Brown
(iii) Grey
(iv) Red
4. In which of the following chemical reaction there is gain of oxygen atoms and loss of hydrogen atoms?
(i) Reduction
(ii) Displacement
(iii) Oxidation
(iv) None of the above
5. Which of the following statement is incorrect about reducing agent?
(i) It gives hydrogen
(ii) It gives oxygen
(iii) It gains oxygen
(iv) It oxidises itself
