Year 8 making salts

Balanced chemical equations can include state symbols and this gives a guide to the method that should be used to make a salt.

Method 1

Base + acid -> salt + water

https://www.focuselearning.co.uk/s/1ljciv1opx8e

(s) + (aq) →(aq) + (l)

Method

1. Add solid base to excess,

2. filter to remove the excess base

3. Collect the filtrate

4. Evaporate the excess water from the solution in an evaporating dish

5. Place the concentrated solution in a crystallising dish.

6. Place the crystallising dish in a warm dry place

7. Wash and dry the crystals.

Method 2

Acid + alkali -> salt + water.

https://www.focuselearning.co.uk/s/qp96anf2uap

https://billvining.com/mmlib_sims/#gen_4_2

(note this a more slightly more advanced method than you used last week)

(aq) + (aq) -> (aq) + (l)

Method:

1. Add the acid to the alkali and use an indicator to work out the volumes of liquids needed.

2. Repeat the reaction using the correct volumes and without the indicator.

3. Evaporate the excess water from the solution in an evaporating dish

4. Place the concentrated solution in a crystallising dish.

5. Place the crystallising dish in a warm dry place

6. Wash and dry the crystals.

https://www.focuselearning.co.uk/s/1ljciv1opx8e

Which method should be used?

CuO(s) + H₂SO₄(aq) → CuSO₄(aq) + H₂O(l)

Which method should be used? CuCO₃(s) + H₂SO₄(aq) → CuSO₄(aq) + H₂O(l) +CO₂

Which method should be used? Mg(s) + H₂SO₄(aq) → MgSO₄(aq) + H₂(g)

Which method should be used? NaOH(aq) + HCl(aq) → NaCl(aq) + H₂O(l)

Which method should be used? KOH(aq) + HCl(aq) → KCl(aq) + H₂O(l)

Which method should be used? KOH(aq) + HNO₃(aq) → KNO₃ (aq) + H₂O(l)

Which method should be used? 2NaOH(aq) + H2SO4(aq) → Na2SO4 (aq) + 2H₂O(l)

Put the steps for making pure dry iron sulfate into the correct order.

1. Filter the excess iron from the iron sulfate (2)
2. Wash the crystals with distilled water and dry the crystals with filter paper (5)
3. leave the concentrated filtrate in an evaporating dish in warm place (4)
4. Firstly add excess iron to the sulfuric acid (1)
5. Heat the filtrate in an evaporating dish (3)

Which acid is used to prepare iron sulphate?

(hint there is only one correct answer)

Which acid is used to prepare iron citrate?

(hint there is only one correct answer)

Which acid is used to prepare iron nitrate?

(hint there is only one correct answer)

Note some metal hydroxides are bases but not alkalis

This is shown by the state symbol for the hydroxide

Magnesium sulfate (which is soluble in water) could be made by

MgO(s) + H₂SO₄(aq) → MgSO₄(aq) + H₂O(l)

Mg(OH)₂(s) + H₂SO₄(aq) → MgSO₄(aq) + 2H₂O(l)

MgCO₃(s) + H₂SO₄(aq) → MgSO₄(aq) + H₂O(l) +CO₂(g)

Hint Mg(OH)2 is insoluble