Hardness of water may be temporary or permanent. Permanent hardness is due to the presence of
a. Chlorides of Ca and Mg in water
b. Sulphates of Ca and Mg in water
c. Hydrogen carbonates of Ca and Mg in water
d. Carbonates of alkali metals in water.
Choose the correct option
1. (a, b)
2. (b, c)
3. (c, d)
4. (a, d)
Match the items in Column I with the relevant items in Column II.
Column I | Column II |
A. Hydrogen peroxide is used as a | 1. Sodium hexametaphosphate |
B. Used in Calgon method | 2. Clark's method |
C. Temporary hardness of hard water is removed by | 3. Reducing agent |
Codes
A | B | C | |
1. | 3 | 2 | 1 |
2. | 1 | 2 | 3 |
3. | 3 | 1 | 2 |
4. | 2 | 1 | 3 |
Given below are two statements:
Assertion (A): | Permanent hardness of water is removed by treatment with washing soda. |
Reason (R): | Washing soda reacts with soluble magnesium and calcium sulphate to form insoluble carbonates. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | (A) is false but (R) is true. |
Which of the following ions will cause hardness in water sample?
1. Ca2+
2. Na+
3. Cl-
4. K+
A water softening reagent among the following is -
1.
2.
3.
4.