1) a) What is an acid?
(1)
b) Give the formulas of hydrochloric, nitric and sulphuric acids. (3)
c) What is the difference between a strong acid and a weak acid?(2)
d) Write an equation to show what happens when the strong acid HCl is added to
water.
(2)
e) Write an equation to show what happens when the weak acid CH3COOH is added to
water.
(2)
2) a) What is a base?
(1)
c) What is the difference between a strong alkali and a weak alkali?(2)
3)
d) Name two strong alkalis.
(2)
e) Name one weak alkali.
(1)
Complete the following equations that are all reactions of acids.
a) potassium hydroxide + nitric acid
(2)
b) hydrochloric acid + sodium oxide
(2)
c) calcium carbonate + sulphuric acid
(2)
d) nitric acid + magnesium
(2)
e) sodium hydrogencarbonate + hydrochloric acid
(2)
f) ammonia + hydrochloric acid
(2)
4) a) What is the name of the reaction between an acid and a base?(1)
b) Write the ionic equation for the reaction of any acid with any alkali.(2)
MAKING SALTS
Complete the table below to show the name of the salt formed when the following acids react
with the following bases.
hydrochloric acid
sulphuric acid
nitric acid
sodium hydroxide
magnesium oxide
potassium carbonate
sodium
hydrogencarbonate
calcium
Now complete the following word equations for reactions between some acids and some
bases.
1) potassium hydroxide + sulphuric acid →
…………………………………………………………………………………
2) nitric acid + sodium oxide →
………………………………………………………………………………………………
3) iron carbonate + nitric acid →
………………………….…………………………………………………………………
4) hydrochloric acid + zinc →
………………………………………………………………………………………………..
5) hydrochloric acid + barium hydroxide →
…………………………………………………………………………………
6) sulphuric acid +potassium hydrogencarbonate→
……………………………..………………………………………
7) iron + hydrochloric acid →
………………………….……………..………………………………………………………
8)
nitric acid + lead oxide → …………………………………………………….…………………………………………..
9) …………………………………………………………………….…… → copper sulphate + water + carbon
dioxide
10) …………………………………………………………………………………………….…… → hydrogen + zinc nitrate
11) copper oxide + …………………………………… → copper sulphate +
…………………………………………….
12) hydrochloric acid + ……………………………………. → ………………………………………..… + lead
chloride
13) ………………………………………… + sulphuric acid → ….……………………………….. + strontium
sulphate
Salt making 1
A sample of nickel sulphate (NiSO4) was made by reacting nickel oxide (NiO), an insoluble base,
with an acid. The acid was warmed in a beaker and nickel oxide added until there was left over
nickel oxide in the beaker. The mixture was filtered giving a green solution. The green solution
partly evaporated and then left to cool for a few hours. The crystals of nickel sulphate were
filtered off, washed and dried.
1) a) Which acid would have been used to make nickel sulphate?
(1)
b) Write a word equation for the formation of nickel sulphate.
(2)
2) a) Why was more nickel oxide added than was needed?
(1)
b) Why was the mixture filtered?
(1)
c) Why was the water not all evaporated from the solution?
(1)
d) Why should the final nickel sulphate crystals not be dried in an oven? (1)
A sample of potassium nitrate was made by reacting potassium hydroxide solution with an acid.
The potassium hydroxide solution was placed in a flask and acid added until the solution was
neutral (this was tested for using a glass rod dipped onto universal indicator paper). The
solution partly evaporated and then left to cool for a few hours. The crystals of potassium
nitrate were filtered off, washed and dried.
3) a) Which acid would have been used to make potassium nitrate? (1)
b) Write a word equation for the formation of potassium nitrate. (2)
c) What colour is potassium nitrate as (i) a solid and (ii) a solution?
(2)
4) a) Why must the reaction mixture not have been acidic before filtering? (1)
b) Why must the reaction mixture not have been alkaline before filtering?
(1)
c) Why was universal indicator paper used to test the pH rather than placing universal
indicator solution into the mixture?
(1)
5)
Describe how you would make a pure, dry sample of magnesium chloride crystals.
(9)
6)
Describe how you would make a pure, dry sample of sodium ethanoate crystals.
(9)
Salt making 2
1)
2)
A sample of lead bromide was made by mixing together solutions of lead nitrate and
sodium bromide. The precipitate was filtered, washed and dried.
a) What is meant by the term precipitate?
(1)
b) What is the precipitate in this experiment?
(1)
c) Write an ionic equation for the formation of this precipitate.
(3)
For each of the following insoluble salts,
i) name two solutions that could be mixed to produce it and
ii) write an ionic equation
a) silver iodide
(5)
b) strontium sulphate
(5)
3)
The salt calcium chloride can be made by the reaction of an acid with calcium
carbonate, an insoluble base
a) Outline the method.
(9)
b) Write a balanced equation for the reaction.
(2)
c) This salt can also be made by direct combination of elements.
i) What does this mean?
(2)
ii) Write a balanced equation for this reaction.
(2)