C4 Reactions of Acids (pg 131)

Question 1

Metal Oxides and Metal Hydroxides are Acids or Bases?

Answer 1

Bases

Question 2

Some metal oxides and metal hydroxides dissolve in what sollution? and what are these soluble compounds?

Answer 2

They disolve in Water, and are alkalis

Question 3

When alkalis react with acids, what is this called?

Answer 3

neutralisation reactions

Question 4

Do bases that won’t dissolve in water still take part in neturalistion reactions with acids?

Answer 4

Yes they will still take part in neturalisation reactions with acids.

Question 5

Metal Oxides and Metal Hydroxides react with acids to form what?

Answer 5

Salt and Water

Question 6

Acid + Metal Oxide react to make?

Answer 6

Salt + Water

Question 7

Acid + Metal Hydroxide reacts to make?

Answer 7

Salt + Water

Question 8

The salts that produced depends upon the acid and the metal ion in the oxide or hydroxide, give examples:

Answer 8

Hydrochoric acid + Copper Oxide &raquo_space;> Copper Chloride + water
2HCl + CuO &raquo_space;> CuCl2 + H20

Sulfuric acid + Potassium hydroxide &raquo_space;> Potassium solfate + water
H2SO4 + 2KOH &raquo_space;> K2SO4 + 2H2O

Nitric Acid + sodium hydroxide &raquo_space;> sodium nitrate + water
HNO3 + NaOH &raquo_space;> NaNO3 + H2O

To work out the formula of an ionic compound you need to balance the charges of the positive and negative ions so the overall charge of a compound is neutral. (for more on ionic formulas see p114).

Question 9

Acids and Metal carbonates produce what?

Answer 9

Salt and water and Carbon Dioxide

Question 10

Metal carbonates are also bases, react with WHAT, to produce a salt, water and carbon dioxide?

Answer 10

they react with ACIDS

Question 11

Acid + Metal Carbonate react to make?

Answer 11

Salt + Water + carbon dioxide

hydrohloric acid + sodium carbonate&raquo_space;> sodium chloride + water + carbon dioxide
2HCl + Na2CO3 &raquo_space;> 2NaCl + H2O + CO2

sulfuric acid + calcium carbonate&raquo_space;> calcium sulfate + water + carbon dioxide
H2SO4 + CaCO3 &raquo_space;> CaSO4 + H2O + CO2

Question 12

How can you make soluble salts using an insoluble base?

Answer 12

You need to pick the right acid and insoluble base, such as an insoluble metal oxide, hydroxide, or carbonate. e.g. if you want to make copper chloride you could mis hydrochloric acid and copper oxide. (CuO (s) + 2HCl (aq) &raquo_space;> CuCl2(aq) + H2O (l))

Gently warm the dilute acid using a bunsen burner, then turn off the bunsen burner.

add the insoluble base to the acid a bit at a time, until no more reacts (i.e. the base even after stirring, the excess solid will just sink to the bottom of the flask)

Then filter out the excess solid to get a salt solution (see pg 101).

To get Pure Solid crystals of the salt, gently heat the solution using a water bath or an electric heater to evaporate some of the water (to make it more concentrated) and then stop heating it and leave the solution to cool. Crystals of the salt should form, which can be filtered out of the solution and then dried. This is called crystallisation (pg 101).

Question 13

Calcium Carbonate is added to hydrochloric acid, Write the word equation and the balanced symbol equation for the reaction that occurs?

Answer 13

Calcium carbonate + hydrochloric acid &raquo_space;> calcium chloride + carbon dioxide + water

CaCO3 + 2HCl &raquo_space;» CaCl2 + CO2 + H2O

(in the exam you could get asked to describe how you would go about making a pure, dry sample or a given soluble salt. make sure you understand the method and what reactants to use.