C6 - Hardness of water Flashcards
1
Q
What will hard water not do when it mixes with soap?
A
It will not form a lather.
2
Q
What is hardness caused by?
A
Calcium or magnesium ions dissolved in the water.
3
Q
What is temporary hardness?
A
Sometimes hardness in water is destroyed when the water is boiled, so it is called temporary hardness.
4
Q
What is permanent hardness?
A
Permanent hardness is when hardness cannot be removed by boiling.
5
Q
What is the equation for temporary hardness?
A
calcium carbonate + carbon dioxide + water = calcium hydrogencarbonate
6
Q
How does an ion-exchange resin work?
A
Water flows over beads of solid resin, which trap the calcium and magnesium ions one its surface.
