1. The temperature of the beaker (i) Increases (ii) Decreases

Question

In the above image, a small amount of quick lime is taken in a beaker and water is added to it slowly. when we touch the beaker we feel that the temperature of the beaker changes.

1. The temperature of the beaker

(i) Increases

(ii) Decreases

2. What is chemical name of the quick lime ?

(i) Calcium hydroxide

(ii) Calcium oxide

(iii) Calcium sulphate

(iv) Calcium phosphate

3. Which of the following type of reaction takes place inside beaker ?

(i) Decomposition reaction

(ii) Percipitation reaction

(iii) Displacement reaction

(iv) Combination reaction

4. Which of the following reactions represent a combination reaction?

(i) CaO(s) + H₂O(l) → Ca(OH)₂(aq)

(ii) CaCO₃(s) → CaO(s) + CO₂(g)

(iii) Zn(s) + CuSO₄(aq) → ZnSO₄(aq) + Cu(s)

(iv)2FeSO₄(s)→Fe₂O₃(s) + SO₂(g) + SO₃(g)

5. State true or false: Quick lime reacts vigorously with water to produce slaked lime releasing a large amount of heat.

(i) TRUE

(ii) FALSE

Answer 1

1. (i) Increases

2. (ii) Calcium oxide

3. (iv) Combination reaction

4. (i) CaO(s) + H₂O(l) → Ca(OH)₂(aq)

5. (i) TRUE