Hard and Soft Water

Hardness in water is caused by the presence of:

• Sodium chloride

• Sodium carbonate

• Calcium chloride

• Potassium nitrate

Permanent hardness in water is caused by the presence of:

• Calcium bicarbonate

• Magnesium sulphate

• Both of them

• None of them

Tags

NGSS.HS-ESS2-5

The process of removing extra common salt from water is called:

• Ionization

• Softening

• Disinfections

• Desalination

The ions that cause hard water are;

• Calcium and Manganese ions

• Calcium and Magnesium ions

• Carbon and Magnesium ions

• Carbon and Manganese ions

Tags

NGSS.HS-ESS2-5

Soft water is water that;

• Does not lather
• Lathers with difficulty
• Lathers easily
• Does not form bubbles

Boiling can be used to make which type (s) of water soft.

• Temporary and  permanent hard water
• Soft water
• Permanently hard water
• Temporary hard water

Tags

NGSS.HS-ESS2-5

The method that uses Na₂CO₃

• baking powder

• salination through baking soda

• desalination through washing soda

• none of the above

Which of these do not cause temporary hardness in water?

• Ca(HCO₃)₂

• Magnesium Bicarbonate

• Calcium Chloride

• Mg(HCO₃)₂

Tags

NGSS.HS-ESS2-5

What percentage of Earth is covered in water?

• 60-65%

• 70-75%

• 50-55%

• 80-85%

What percentage of water is salt water?

• 97%

• 98%

• 99%

• 90%