1.) What is a balanced chemical equation?

2.) Write down the balanced chemical equation of the reaction between zinc and hydrochloric acid. What type of chemical reaction is this?

3.) What is endothermic reaction?

4.) What is a formula equation?

5.) What is the meaning of '+' between the reactants and 'A' above the arrow head in a chemical equation?

6.) What is a chemical reaction? In how many ways can chemical reactions take place?

7.) Enlist any four examples of chemical change.

8.) What do you mean by a diatomic element? Give any four examples.

9.) List out the information that can be obtained from a balanced chemical equation?

10.) Enlist the limitation of a balanced chemical reaction.

11.) What would be the exothermic and endothermic reactions while Sanjay is cooking rice on a firewood stove?

12.) When you touch outside the beaker containing two chemicals reacting together, you feel hot. What type of chemical reaction is going on in the beaker? Explain with an example.

13.) Are chemical reactions important to life? Explain.

14.) Mention the steps of the method of writing a balanced chemical reaction with an example.

15.) Differentiate between physical change and chemical change.

16.) Differentiate between skeletal chemical equation and balanced chemical equation.

17.) Differentiate between endothermic reaction and exothermic reaction.

18.) Change the following word equations into the balanced equations. a. Hydrogen + Chlorine → Hydrogen chloride b. Hydrogen + Nitrogen - Ammonia C. Potassium chlorate → Potassium chloride + Oxygen d. Zinc+ Hydrochloric acid →Zinc chloride + Hydrogen e. Copper

19.) What happens when magnesium burns in oxygen?

20.) What happens when calcium carbonate is heated?

21.) What happens when hydrogen reacts with nitrogen at necessary conditions?

22.) What happens when potassium hydroxide reacts with nitric acid?

23.) What happens when carbon dioxide is treated with limewater?

24.) Define matter with example.

25.) Define physical change and chemical change with example.

26.) Write the differences between physical change and chemical change.

27.) What is a chemical reaction? Explain it with an example.

28.) Define the following terms: Chemical equation, reactants and products.

29.) Define word equation and formula equation.

30.) What is a balanced chemical equation?

31.) State the method for writing a balanced chemical equation.

32.) List out the information that can be obtained from a balanced chemical equation.

33.) Write any five limitations of a chemical equation.

34.) What do you mean by catalyst?

35.) What is meant by endothermic and exothermic reaction?

36.) List the type of chemical reaction on the basis of their nature.

37.) Define addition reaction with examples.

38.) Define decomposition reaction.

39.) Define displacement reaction.

40.) Define Acid-Base reaction with example.

41.) Define molecular weight.

42.) Define gram molecular weight.

43.) Define Avogadro’s number or one mole.

44.) What is meant by the solubility of a substance?

45.) Define the terms ‘solute’ and ‘solvent’ with one example of each.

46.) What do you mean by ‘solution’? Give one example.

47.) Unsaturated solution

48.) Saturated solution

49.) Supersaturated solution

50.) What is a solubility curve? What can be known from the solubility curve?

51.) Dilute solution

52.) Concentrated solution

53.) The differences between saturated and unsaturated solution

54.) The differences between dilute and concentrated solution

55.) List any four importance of a solution.

56.) List any three applications of a solubility curve.

57.) What is crystal? How are crystals prepared?

58.) What is crystallization?

59.) Define Homogeneous mixture and heterogeneous mixture with examples.

60.) List the types of mixture on the basis of size of particle.

61.) Solution

62.) Colloids

63.) Suspension

64.) Why does a solute dissolve quickly at high temperature and at powdered state?

65.) When a saturated solution at a high temperature is cooled, why is the solution separated out as a solid?

66.) If some solute added can be dissolved in a solution at a certain temperature, what is the type of solution?

67.) Temperature is mentioned along with the solubility of a substance. Why?

68.) If the crystals of copper sulphate are kept in its saturated and supersaturated solution separately, what will happen to the crystals?

69.) The solubility of CaSO4 at 20°C is 21. What does it mean?

70.) If the concentration of a solution reduces and crystal appear when solute is added to the solution at temperature 40°C, name the type of solution.

71.) What happens when a saturated solution of NaCl is cooled? What are crystalline and amorphous substances?