Temporary Hardness

Q.

The temporary hardness of water is due to the presence of:

1. Magnesium bicarbonate

2. Calcium chloride

3. Magnesium sulphate

4. Calcium carbonate

Q. The temporary hardness of water can be removed by:

1. boiling

2. addition of potassium permanganate

3. cooling

4. addition of chlorine

Q. Name two substances that are responsible for hardness of water.

Q.

Permanent hardness is caused by the dissolved __(sulphates/bicarbonates) of calcium and magnesium.

Q. Temporary hardness of water can be removed by addition of chlorine.

1. True
2. False

Q.

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

1. For temporary hardness:- $N{a}_{2}C{O}_3$

   For permanent hardness:- $Ca(OH{)}_2$

2. For temporary hardness:- $Ca(OH{)}_2$

   For permanent hardness:- Boiling

3. For temporary hardness:- Boiling

   For permanent hardness:- $Ca(OH{)}_2$

4. For temporary hardness:- Boiling

   For permanent hardness:- $N{a}_{2}C{O}_3$

Q. Name two substances that are responsible for hardness of water.

Q.

What is the difference between temporary and permanent hardness in water?

Q.

How can the temporary hardness of water remove? Explain with equation.

Q.

Give balanced equations to show

1. how temporary hardness enters into water
2. temporary hardness in water can be removed by boiling.
3. permanent hardness in water can be removed by adding washing soda

Q.

A water sample contains magnesium bicarbonates. It does not lather with soap. How can we make the water sample useful for cleaning clothes?

1. Boiling

2. Cooling

3. By addition of sodium

4. By addition of water

Q.

The reaction involved in the removal of temporary hardness of water is:

1. Ca(${HCO}_3$)${}_2$ $\stackrel{heat}{\to }$ ${CaCO}_3$ + $H_2$O + $C{O}_2$ $\uparrow$

2. $CaC{l}_2$ +$N{a}_2$$C{O}_3$ $\to$ $CaC{O}_3$ $\downarrow$ + 2NaCl
3. 2$CaC{l}_2$ + (${NaPO}_3$)${}_6$ $\to$ $N{a}_2$[$C{a}_2$($P{O}_3$)${}_6$] + 4NaCl
4. $MgS{O}_4$ + $N{a}_2$$A{l}_2$$S{i}_2$$O_8$.x$H_2$O $\to$ Mg$A{l}_2$$S{i}_2$$O_8$.x$H_2$O + $N{a}_2$$S{O}_4$

Q. if permanent hardness of water can be treated i.e., can be removed, then why is it called permanent hardness of water?

Q.

The reaction involved in the removal of temporary hardness of water is:

1. $\text{Ca}({\text{HCO}}_3$)${}_2$ $\stackrel{\text{Heat}}{\to }$ ${\text{CaCO}}_3+{\text{H}}_2\text{O}+{\text{CO}}_2\uparrow$

2. ${\text{CaCl}}_2+{\text{Na}}_2{\text{CO}}_3$ $\to$ ${\text{CaCO}}_3(\downarrow )+2\text{NaCl}$
3. ${\text{MgSO}}_4+$ ${\text{Na}}_2{\text{Al}}_2{\text{Si}}_2{\text{O}}_8.{\text{xH}}_2\text{O}$ $\to$ ${\text{MgAl}}_2{\text{Si}}_2{\text{O}}_8.{\text{xH}}_2\text{O}+{\text{Na}}_2{\text{SO}}_4$
4. ${\text{2CaCl}}_2+({\text{NaPO}}_3$)${}_6$ $\to$ ${\text{Na}}_2[{\text{Ca}}_2{\text{PO}}_3$)${}_6$] + $\text{4NaCl}$

Q.

The temporary hardness of water is due to the presence of:

1. magnesium bicarbonate

2. calcium chloride

3. magnesium sulphate

4. calcium carbonate

Q. During softening of water, boiling is followed by:

1. evaporation
2. distillation
3. filtration
4. freezing

Q. Difference bet. temporary and permanent hardness of water