Permanent hardness of water can be removed by adding? A) Potassium permanganate B) Chlorine C) Bleaching powder D) Sodium Carbonate Related MCQs: The permanent hardness of water due to sulphates of metals can be removed by the use of? Which element is used to remove the permanent hardness of water? Less than one percent of Earth’s water is fresh water but the oceans contain ….. percent of the earth’s water? In a mixture of 60 liters, the ratio of milk and water is 2:1. What amount of water must be added to make the ratio of milk and water as 1:2?