Making Soluble Salts

Question 1

How do we make soluble salts?

Answer 1

By neutralising acids and crystallising the resulting solution.

Question 2

What is the equation to make a soluble salt?

Answer 2

Acid(aq) + Base(s)/Alkali(aq) -> Salt (aq) + water(l)

Question 3

What 2 ways can you make soluble salts?

Answer 3

1. The insoluble base method
2. The titration method

Question 4

What 2 things can the base be in the insoluble base method?

Answer 4

It’s usually a metal oxide but can be a solid metal carbonate.

Question 5

In the insoluble base method, why do we have to add the base until no more will dissolve?

Answer 5

We can guarantee the base is in excess so we know all the acid has bee used up.

Question 6

When do we use the titration method instead of the insoluble base method?

Answer 6

When making salts that contain Na+, K+ or NH4+ ions, because their bases are all soluble so you wouldn’t be able to filter out the excess if you used the insoluble base method.

Question 7

What alkalis are usually used in the titration method?

Answer 7

NaOH, KOH or NH4OH

Question 8

What are the 4 steps of crystallisation after achieving the salt solution?

Answer 8

1. Heating the salt solution until crystals form
2. Leaving them in an evaporating basin for a few days
3. Filtering crystals to get rid if excess salt solution
4. Dabbing crystals dry with filter paper