Formulae of Ionic Compounds

Question 1

What are compound ions?

Answer 1

ions that contain atoms of two different elements

Question 2

What name do positively charged ions (formed from hydrogen or metal) take?

Answer 2

the name of the element

Question 3

What name do negatively charged ions formed from single non-metal atoms take?

Answer 3

the name of the element, but ending in -ide

Question 4

What name do negatively charged ions in compounds (with 3 or more elements) containing oxygen take?

Answer 4

they end in -ate

Question 5

Write down the formula of these ionic compounds:

(a) sodium fluoride
(b) magnesium oxide
(c) iron(III) oxide
(d) sodium nitrate
(e) barium nitrate

nitrate: NO₃⁻

Answer 5

(a) NaF
(b) MgO
(c) Fe₂O₃
(d) NaNO₃
(e) Ba(NO₃)₂

(use brackets for compound ions)

Question 6

Give the formulae of these ionic compounds:

(a) calcium sulfide
(b) iron(II) chloride
(c) ammonium hydroxide
(d) ammonium carbonate
(e) sodium sulfate

ammonium: NH₄⁺
hydroxide: OH⁻
carbonate: CO₃²⁻
sulfate: SO₄²⁻

Answer 6

(a) CaS
(b) FeCl₂
(c) NH₄OH
(d) (NH₄)₂CO₃
(e) Na₂SO₄