Chem 1, Unit 7

What causes permanent hardness of water?

• Chloride and Sulfate salts of Calcium and Magnesium

• Sodium and Potassium salts

• Chloride and Sulfate salts of Sodium and Potassium

• Calcium and Magnesium salts of Sodium and Potassium

Tags

NGSS.HS-ESS2-5

Which of the following compounds is NOT involved in permanent hard water?

• Calcium Chloride - CaCl₂

• Magnesium Chloride - MgCl₂

• Calcium Sulfate - CaSO₄

• Sodium Chloride - NaCl

Tags

NGSS.HS-ESS2-5

Permanent hard water can be removed by boiling.

• True

• False

Which chemical can be added to remove permanent hard water?

• Sodium Carbonate - Na₂CO₃

• Calcium Carbonate - CaCO₃

• Magnesium Carbonate - MgCO₃

• Potassium Carbonate - K₂CO₃

Why should hard water be avoided as a dilutant for embalming fluid?

• It causes the blood to coagulate and interferes with the blood drainage process.

• It enhances the preservation of the body.

• It makes the embalming fluid more effective.

• It has no effect on the embalming process.

What is the term used when a substance is intentionally caused to lose water?

• Dehydration

• Desiccation

• Evaporation

• Condensation

Water is hard when it contains:

• Acid solution

• Precipitate in suspension

• Dissolved sodium salts

• Dissolved Ca and Mg salts

Hardness in water is caused by the presence of:

• Sodium chloride

• Sodium carbonate

• Calcium chloride

• Potassium nitrate

Tags

NGSS.HS-ESS2-5

Permanent hardness in water is caused by the presence of:

• Calcium bicarbonate

• Magnesium sulfate

• Both of them

• None of them

Tags

NGSS.HS-ESS2-5

How can the presence of hard water be detected at home?

• By measuring the pH level of the water

• By observing the lather of soap

• By checking the color of the water

• By tasting the water