carbon dioxide

bleaching powder

sulphur dioxide

chloramines

increases

decreases

remains unaffected

none of the above

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