Permanent Hardness

Q.

A saturated solution is the solution in which

1. No more amount of substances can be added

2. Adding of substance depends upon solution

3. None of the given options

4. More substances can be added to the solution on heating

Q.

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 water-soluble compounds.

1. (A) and (R) both are correct and (R) is the correct explanation of (A).

2. (A) is not correct but (R) is correct.

3. (A) is correct but (R) is not correct.

4. (A) and (R) both are correct but (R) is not the correct explanation of (A).

Q.

Permanent hardness of water can be removed by adding ____.

1. Sodium carbonate

2. Sodium bicarbonate

3. Calcium sulphate

4. Sodium chloride

Q.

Which of the following is not true?

1. Permanent hardness can be removed by boiling the water

2. Hardness of water depends on its behaviour towards soap

3. The temporary hardness is due to the presence of Ca and Mg bicarbonates

4. Permanent hardness is due to the presence of soluble Ca and Mg sulphates, chlorides and nitrates

Q. Rahul took 25 ml of sea water in a beaker and added one spoon of sodium carbonate to it. Which of the following will he observe?

1. Bubbles are formed
2. Precipitate is formed
3. Solution colour changes to blue
4. Solution colour changes to red

Q. Which of the following processes will produce hard water?

Q.

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 water-soluble compounds.

1. (A) and (R) both are correct but (R) is not the correct explanation of (A).

2. Statements (A) and (R) both are correct and (R) is the correct explanation of (A).

3. (A) is not correct but (R) is correct.

4. (A) is correct but (R) is not correct.

Q. Rahul took 25 ml of sea water in a beaker and added one spoon of sodium carbonate to it. Which of the following will he observe?

1. Solution colour changes to blue
2. Precipitate is formed
3. Solution colour changes to red
4. Bubbles are formed

Q. Assertion (A): Hardness of water is removed by treatment with sodium carbonate.
Reason (R): Sodium carbonate reacts with soluble magnesium and calcium chloride to form water soluble compounds.

1. (A) and (R) both are correct but (R) is not the correct explanation of (A).
2. (A) is correct but (R) is not correct.
3. (A) and (R) both are correct and (R) is the correct explanation of (A).
4. (A) is not correct but (R) is correct.

Q.

Temporary and permanent hardness of water can be removed by:-

1. 

2. Scum formed by lathering soap

3. Dilute

4. Zn-Cu couple