Home
Class 12
CHEMISTRY
Water is said to be permanently hard whe...

Water is said to be permanently hard when it contains

A

Chlorides and sulphates of Mg and Ca:

B

Bicarbonates of Na and K

C

Carbonates of Na and K

D

Phosphates of Na and K

Text Solution

Verified by Experts

The correct Answer is:
A
Promotional Banner

Topper's Solved these Questions

Similar Questions

Explore conceptually related problems

A water sample is said to contain permanent hardness if water contains

Explain with equation, what is noticed when permanent hard water is treated with slaked lime

Give a balanced equation for the following conversions: Calcium sulphate in permanent hard water to calcium carbonate using sodium carbonate.

The Reagent which is commercially known as ‘calgon’ that is used to remove the permanent hardness of water in Calgon’s method. Find out the number of moles of calgon required to remove 12 moles of Ca^(2+) ion present in hard water.

Hard water does not contain :-

25mL samples of distiled water, tap water and boiled water required, respectively, 1mL, 13mL and 5mL of soap solution to form a permanent lather. The ratio of temporary to permanent hardness in the tap water is

Give balanced equations to show how - Permanent hardness in water can be removed by addition of washing soda

Calculate milli equilvalent of washing soda required to remove its hardness from one litre hard water contains "18.00 mg Mg"^(2+)

A water is said to be soft water if it produces sufficient foam with the soap and water that does not produce foam with soap is known as hard water. Hardness has been classified into two types (i)Temporary hardness (ii) Permanent hardness. Temporary hardness is due to presence of calcium and magnesium bicarbonate. It is simply removed by boiling as Ca(HCO_(3))_(2)overset(Delta)rarr CaCO_(3)darr+CO_(2)uarr+H_(2)O Mg(HCO_(3))_(2)overset(Delta)rarr MgCO_(3)darr+CO_(2)uarr+H_(2)O temporary hardness can also be removed by addition of slaked lime, Ca(OH)_(2) Ca(HCO_(3))_(2)+Ca(OH)_(2) to 2CaCO_(3)darr+2H_(2)O permanent hardsness is due to presencce of sulphates and chlorides of Ca,Mg,etc. It is removed by washing soda as CaCl_(2)+Na_(2)CO_(3) to CaCO_(3)darr+2NaCl CaSO(4)+Na_(2)CO_(3)to CaCO_(3)darr+Na_(2)SO_(4) Permanent hardness also removed by ion exchange resin process as 2RH+Ca^(2+)toR_(2)Ca+2H^(+) 2ROH+SO_(4)^(2-) to R_(2)SO_(4)+2OH^(-) The degree of hardness of water is measured in terms of PPm of CaCO_(3) 100 PPm means 100 g of CaCO_(3) is present in 10^(6) g of H_(2)O . If any other water sample which contain 120 PPm of MgSO_(4) , hardness in terms of CaCO_(3) is equal to =100 PPm. One litre of a sample of hard water (d=1 g/mL) cotains 136 mg of CaSO_(4) and 190 mg of MgCl_(2) . What is the total hardness of water in terms of CaCO_(3) ?

Which anions produce permanent hardness in water?