Water

Question 0

What can cause calcium and magnesium ions to get into water?

Answer 0

The water having flowed through rocks which contained magnesium sulphate calcium sulphate four example limestone and chalk.

Question 1

What makes water hard?

Answer 1

Calcium ions and magnesium ions.
C a T.
Mag 2.

Question 2

What does hard water form when heated?

Answer 2

Scale.

Question 3

What sort of water makes a better lather of soap?

Answer 3

Soft

Question 4

What are the benefits of hard water?

Answer 4

It’s good for bones and teeth

People are less likely to have heart disease

Question 5

What are the two types of hard water?

Answer 5

Temporary and permanent

Question 6

What causes temporary hardness?

Answer 6

The Hydrogen carbonate ion

HCO3 minus

Question 7

What causes permanent hardness?

Answer 7

Dissolved calcium Sulfate

Question 8

How do you remove temporary hardness?

Answer 8

Boilin
Or washing soda
Or ion exchange columns

Question 9

How does boiling remove temporary hardness?

Answer 9

It decomposes the calcium hydrogen carbonate and makes calcium carbonate, water and CO2

Question 10

Does boiling get rid of permanent hardness?

Answer 10

No

Question 11

What types of hardness can washing soda soften?

Answer 11

Both temporary and permanent.

Question 12

What softens permanently hard water?

Answer 12

Ion exchange columns and washing soda

Question 13

What is washing soda called?

Answer 13

Sodium carbonate

Question 14

What is the formula for sodium carbonate?

Answer 14

Na2CO3

Question 15

How does washing soda soften permanent hardness?

Answer 15

The added carbonate ions react with the ions and make a precipitate of either magnesium or calcium carbonates.
They’re no longer dissolved and don’t make it hard.

Question 16

What is produced when permanently hard water has soda added to it?

Answer 16

CaCO3

Question 17

What type of hardness is removed by ion exchange columns?

Answer 17

Both temporary and permanent.

Question 18

How does an ion exchange column work?

Answer 18

The columns have lots of sodium ions which are ‘exchanged’ with the calcium and magnesium ions.

Question 19

Give a method of comparing the hardness of water.

Answer 19

Titration

Question 20

What is put in the Burette in the titration of water samples?

Answer 20

Soap solution.

Question 21

What are the processes in water treatment?

Answer 21

Screens- mesh screen
Sedimentation- sticking pieces together
Filtering through gravel beds
Chlorination

Question 22

What can people buy to make their water cleaner?

Answer 22

They can buy carbon or silver filter.

Question 23

What does a carbon filter remove?

Answer 23

The chlorine taste.

Question 24

What does silver filters remove?

Answer 24

They kill bugs

Question 25

How can you make pure water?

Answer 25

Distillation

Question 26

What is distillation?

Answer 26

Boiling water to make steam and condensing it.

Question 27

Why don’t we condense most water?

Answer 27

Because it is expensive

Question 28

What are the advantages of adding Fluorine to water?

Answer 28

It helps reduce tooth decay.

Question 29

What are the problems with adding fluorine to water?

Answer 29

It can cause cancer and vibe problems
It needs to be constantly monitored
Mass medication

Question 30

Why is chlorine added to drinking water?

Answer 30

It prevents disease.

Question 31

What are the problems with chlorine in water supplies?

Answer 31

It can react with other substances and create toxins

Some studies link it to cancers