Water Hardness Quiz

What causes hardness in water?

• Sodium chloride

• Potassium nitrate

• Calcium and magnesium salts

• Carbon dioxide

Which of the following is a characteristic of hard water?

• Forms lather easily with soap

• Tastes salty

• Forms scum with soap

• Boils at a lower temperature

Which of these ions is NOT responsible for water hardness?

• Calcium ions

• Magnesium ions

• Iron ions

• Sodium ions

What is temporary hardness mainly caused by?

• Calcium sulfate

• Magnesium sulfate

• Calcium bicarbonate

• Sodium chloride

Temporary hardness can be removed by:

• Freezing

• Filtration

• Boiling

• Chlorination

Which of the following compounds causes permanent hardness?

• Calcium bicarbonate

• Magnesium bicarbonate

• Calcium sulfate

• Carbonic acid

What is used in ion-exchange method to soften water?

• Charcoal

• Resin

• Sand

• Salt

Soft water is defined as water that:

• Has a low pH level

• Has no dissolved gases

• Contains very low levels of calcium and magnesium

• Has a high concentration of sodium chloride

Which of the following is a disadvantage of hard water?

• It tastes sweet

• It leads to corrosion

• It causes scaling in pipes and boilers

• It increases soap efficiency

Which one of the following methods can remove both temporary and permanent hardness?

• Boiling

• Ion exchange

• Sedimentation

• Aeration