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Flashcards in water (further) Deck (16)
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1
Q

How do we purify water?

A

filtration and adding chlorine

2
Q

Why do we filter water?

A

remove all solids

3
Q

Why do we add chlorine to water?

A

kill bacteria

4
Q

Why is fluoride added to water?

A

to improve teeth

5
Q

Why is adding fluoride not accepted by some people?

A

they haven’t been given a choice

6
Q

When can dirty water become a large problem?

A

3rd world countries

7
Q

How does calcium and magnesium get into water?

A

dissolves from washing over rocks

8
Q

What does calcium and magnesium make water?

A

hard

9
Q

What is scum?

A

insoluble black solid formed when hard water reacts with soap

10
Q

What is scale?

A

calcium/magnesium carbonate, insoluble

11
Q

How is hard water good for our health?

A

good for teeth and bones and for preventing heart disease

12
Q

What is a disadvantage of hard water?

A

difficult to make lather

13
Q

How can we test for hardness?

A

measuring how much froth comes from adding soap and shaking, the higher the froth the softer the water

14
Q

How does an ion exchange column soften water?

A

replaces sodium ions for Mg/Ca ions

15
Q

What does adding sodium carbonate do to hard water?

A

softens it, Ca and Mg form precipitates

16
Q

How can we remove temporary hardness?

A

boiling