Hard and Soft Water

Permanent hardness in water is caused by the presence of:

• Calcium bicarbonate

• Magnesium sulphate

• Both of them

• None of them

What is the main cause of temporary hardness in water?

• Calcium bicarbonate

• Magnesium chloride

• Sodium chloride

• Potassium nitrate

Tags

NGSS.HS-ESS2-5

Which of the following methods can be used to remove permanent hardness from water?

• Boiling

• Adding baking soda

• Ion exchange

• Filtration

What is the chemical formula for calcium carbonate, a compound that contributes to water hardness?

Which ion is primarily responsible for the hardness of water?

• Sodium ion

• Calcium ion

• Potassium ion

• Chloride ion

What is the effect of hard water on soap?

• Increases lather formation

• Decreases lather formation

• No effect

• Enhances cleaning

Which of the following is a common test to determine water hardness?

• pH test

• Turbidity test

• Titration with EDTA

• Boiling test

What is the main disadvantage of using hard water in industrial boilers?

• Corrosion

• Scale formation

• Increased efficiency

• Reduced fuel consumption

Which of the following is a natural source of soft water?

• Rainwater

• Seawater

• Groundwater

• River water

What is the role of a water softener in treating hard water?

• Adds calcium ions

• Removes calcium and magnesium ions

• Increases pH

• Decreases pH