methods of removing hardness from water

Question 1

What are the 3 main methods of removing both temporary and permanent water hardness?

Answer 1

1. distillation
2. using washing soda
3. ion-exchange resin

Question 2

Explain the process of distilation

Answer 2

the water is boiled off through a Liebeg condenser and the hydrogen carbonates and sulfates remain in the flask.

Question 3

what is the main flaw about distillation in order to remove both types of hardness?

Answer 3

this is too expensive on a large scale

Question 4

what instrument is used in the distillation of water?

Answer 4

liebeg condenser

Question 5

explain the process of the addition of washing soda crystals in order to remove water hardness

Answer 5

the carbonate ions in the washing soda crystals react with the calcium ions that cause the hardness (both) and thus remove them.
they react to form insoluble calcium carbonate

Question 6

What is the chemical name and formula for washing soda crystals?

Answer 6

hydrated sodium carbonate

Na2CO3·10H2O

Question 7

give the formula for the reaction that takes place when washing soda crystals are added to water

Answer 7

Ca^2+ + CO3^2- —> CaCO3↓

Question 8

What plays no part in the reaction to form calcium carbonate when adding washing soda crystals to water?

Answer 8

the Na^2+ from the washing soda crystals/sodium carbonate do not play any part in the reaction - they simply remain dissolved in the water

Question 9

softening water by the ion-exchange resin process will be studied in the next deck

Answer 9

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