Ionic Equations

Question 1

ion

Answer 1

an electrically charged particle

is formed when an atom or group of atoms loses or gains electrons

Question 2

hydrogen and metal ions

Answer 2

hydrogen and metal atoms usually LOSE electrons to form POSITIVELY charged ions

Question 3

non-metal ions

Answer 3

GAIN electrons to form NEGATIVELY charged ions

Question 4

How do you represent ions?

Answer 4

using a superscript + or -

Question 5

What happens when oppositely charged ions in a solution are joined?

Answer 5

they form an insoluble solid called a precipitate

e.g.
silver ions and chloride ions in solution form solid silver chloride
Ag[+] (aq) + Cl[-] (aq) -> AgCl(s)

Question 6

rules of writing an ionic equation (4)

Answer 6

• all substances are shown by their formula
• the number of atoms in a substance (e.g. O[2]) isn’t shown
• the numbers of atoms of each element in the reactants and products are the same
• the total electrical charge is the same on both sides of the equation

(a number may need to be written in front of a substance to balance the equation)

Question 7

Magnesium reacts with copper sulfate solution to form copper and magnesium sulfate solution.

a) Write a balanced equation for this reaction. [1]
b) Write a balanced ionic equation for this reaction. [2]

Answer 7

a) Mg + CuSO[4] -> Cu + MgSO[4]

b) Mg + Cu[2+] -> Cu + Mg[2+]

Question 8

Lead(II) ions, Pb[2+], react with bromide ions, Br[-].
Cream coloured lead(II) bromide forms, PbBr[2].
Write an ionic equation for the reaction. [1]

Answer 8

Pb[2+] + 2Br[-] -> PbBr[2]

Question 9

Barium chloride solution, BaCl2, reacts with sodium sulfate solution, Na[2]SO4.
Solid barium sulfate, BaSO4, and sodium chloride solution, NaCl(aq), form.

a) Write the balanced equation. [1]
b) Write an ionic equation for this reaction. [1]

Answer 9

a) BaCl2 + Na[2]SO[4] -> BaSO[4] + 2NaCl(aq)

b) Ba2+ + SO[4]2- -> BaSO4