smaller

larger

same

none of the above

reduced at higher pH value of water

unaffected by pH value of water

increased at higher pH value of water

highest at pH value equal to 7

only carbonate hardness is removed

only non-carbonate hardness is re-moved

lime reduces the carbonate hardness and soda-ash removes the non-carbo¬nate hardness

lime reduces the non-carbonate hard-ness and soda-ash removes the carbo¬nate hardness

it is unsuitable for turbid and acidic water

huge amount of precipitate is formed which creates a disposal problem

the effluent cannot be reduced to zero hardness

it is unsuitable for softening the water of excessive hardness

sodium sulphate

copper sulphate

sodium chloride

calcium chloride