Effects of Hardness

Q. Which gas is evolved when calcium bicarbonate undergoes boiling?

1. Hydrogen
2. Carbon monoxide
3. Carbon dioxide
4. Dioxygen

Q. Statement 1: It is not safe to use hard water in industrial boilers.
Statement 2: Calcium carbonate is a good conductor of heat.

1. Statement 1 is correct but statement 2 is incorrect
2. Statement 2 is correct but statement 1 is incorrect
3. Both statement 1 and statement 2 are correct
4. Both statement 1 and statement 2 are incorrect

Q. Predict the products obtained when calcium bicarbonate undergoes boiling.

1. Calcium carbonate
2. Carbon dioxide
3. Calcium hydroxide
4. Water

Q. Boilers are commonly used in industries to

1. remove hardness of water
2. produce water with ${\text{Ca}}^{2+}$ ions
3. freeze water
4. produce super heated steam

Q. When utensils are washed with hard water, they tend to lose their lustre.

1. True
2. False

Q. Hard water is safe and economical to be used in industries.

1. True
2. False

Q.

The hardness of water is due to the presence of:

1. Calcium and Magnesium salts

2. Sodium and Magnesium salts

3. Calcium and Sodium salts

4. None of these

Q.

Saturation with which of the following substances will produce hard water?

1. Saturation of water with $CaC{O}_3$

2. Saturation of water with $MgC{O}_3$

3. Saturation of water with $CaS{O}_4$

4. Saturation of water with $N{a}_{2}S{O}_4$

Q. Carnallite is the mineral of:

1. $Na$
2. $Ca$
3. $Mg$
4. none of the above

Q.

Hard water gives lather with soap easily.

1. True

2. False

Q. Choose the correct option regarding the following assertion and reason.

Assertion: Use of hard water in industrial boilers reduces heating efficiency.
Reason: Hard water produces scales on the inner walls of the boilers.

1. Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
2. Both Assertion and Reason are true and Reason is not the correct explanation of Assertion.
3. Both Assertion and Reason are false
4. Only Assertion is true.