Chapter 29 - Water Hardness

Question 1

How is hard water formed?

Answer 1

It is formed when water (excellent solvent) dissolves calcium ions or magnesium ions as it passes through various rocks (mainly limestone)

Question 2

What happens when the ions in hard water react with soap?

Answer 2

They form an insoluble compound which floats on top of water as scum

Question 3

What is soft water ?

Answer 3

Water that lathers easily with soap

Question 4

How can water be softened?

Answer 4

💧 Boiling
💧 Distillation
💧 Ion exchange

Question 5

Explain how ion exchange works

Answer 5

As water passes through the ion exchanger, calcium and magnesium ions are swapped for sodium ions giving you soft water

Question 6

What are the advantages of hard water?

Answer 6

👍🏻 Good source of calcium
👍🏻 Tastes nicer
👍🏻 Good for tanning and brewing

Question 7

What are the disadvantages of hard water?

Answer 7

👎🏻 Limescale blocks pipes and leaves scale on kettles and pipes
👎🏻 Wastes soap
👎🏻 Produces scum with soap

Question 8

What is hard water?

Answer 8

Water that doesn’t lather easily with soap