<prompt> Which of the following do not cause hardness of water ?Calcium carbonateCalcium sulphateCalcium bicarbonateMagnesium bicarbonate  <response>: Temporary hardness is a type of water hardness caused by the presence of dissolved bicarbonate minerals calcium bicarbonate and magnesium bicarbonate. Permanent hardness is caused by dissolved calcium sulfate which is not removed by boiling ref : park 21st ed 