C2 - Making Salts

Question 1

Why can’t you use the same method for making a soluble salt using an alkali and doing so with a metal?

Answer 1

You can’t tell when the reaction has finished when using alkalis.

Question 2

How do you make soluble salts using an alkali? [4]

Answer 2

1) add the exact right amount.
2) use indicator to show when the reaction has finished.
3) repeat using the same volumes but without indicator.
4) crystallise.

Question 3

What type of reaction is involved when making insoluble salts?

Answer 3

Precipitation.

Question 4

How do you make insoluble salts? [3]

Answer 4

1) pick two solutions containing the correct ions & mix.
2) filter the salt out.
3) wash & dry the salt.

Question 5

What can precipitation reactions be used for regarding water? [3]

Answer 5

1) to remove poisonous ions like lead.
2) to remove water hardness.
3) to treat sewage.

Question 6

How do you make a soluble salt using a metal/insoluble base? [4]

Answer 6

1) add the metal to the acid - the solid will dissolve.
2) when neutralised the excess will sink to bottom.
3) filter excess.
4) crystallise: evaporate water.