Fill in the blanks :
1. Ice changing to water is an example of ....................... change.
2. When copper powder is heated, ....................... is formed.
3. The substances that undergo changes are called as .......................
.
.
4. Reactants are represented on ................... .
5. Products are represented on ..................... .
6. Conversion of oil to fats requires ....................... as catalyst.
7. When vegetable oil is mixed with nickel as a catalyst, and heat it with hydrogen gas ....................... are obtained on cooling.
8. The simple form of representation of chemical reaction in words is called .............. .
9. If reactants or products are present as solution in excess of water, the symbol used is ....................... .
10. According to ......................., the total mass of reactants is equal to the total mass of products during a chemical reaction.
*11. The chemical formula of POP is ............ .
*12. The chemical reaction during which hydrogen is lost is called as ....................... .
*13. Corrosion can be prevented by using ....................... .
*14. When acids and alkalis react together, ....................... and ....................... is formed.
*15. The chemical reaction in which heat is evolved is called as ....................... reaction.
16. When oil and fats are oxidized or even allowed to stand for a long time, they become ....................... .
A. Answers
1. Physical
2. Copper oxide
3. Reactants
4. Left hand side
5. Right hand side
6. Nickel
7. Fats
8. Word equation
9. Aq
10. Law of conservation of mass
11. (CaSO4).H2O
12. Oxidation reaction
13. Anti rust solution, coating surface by p;aint, process like galvanizing and electro – plating
14. Salt and water
15. Exothermic reaction
16. Rancid.
