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WorksheetsWAEC Chemistry IUPAC
Total questions: 46
Worksheet time: 49mins
What is the oxidation number of nitrogen in NH₄+?
+1
+3
-3
-1
The compound with the formula Na₂CO₃ is called
Sodium carbonate
Sodium hydrogen carbonate
Sodium oxide
Disodium trioxide
Which of the following is a trivalent element?
Magnesium
Aluminium
Calcium
Sodium
The IUPAC name for CaCl₂ is
Calcium dichloride
Calcium chloride
Dicalcium chloride
Calcium(II) chloride
The formula of the sulphate radical is
SO₃²⁻
SO₄²⁻
HSO₃⁻
SO₂
What is the electronic configuration of oxygen (atomic number 8)?
2,6
2,8
8
6,2
Which of the following ions has a valency of 1?
SO₄²⁻
NO₃⁻
CO₃²⁻
SO₃²⁻
The radical NH₄+ is known as
Ammonium
Ammonia
Nitrite
Nitrate
The IUPAC name of Fe₂O₃ is
Iron oxide
Iron(II) oxide
Iron(III) oxide
Ferric oxide
How many electrons are in the outermost shell of an atom with configuration 2,8,3?
2
3
5
8
The formula for aluminium trioxonitrate(V) is
Al(NO₂)3
Al(NO₃)3
AlN₃
Al₃NO₃
Which of the following elements is divalent?
Calcium
Potassium
Aluminium
Nitrogen
Which of the following compounds is correctly named?
Na₂SO₃: Sodium sulphate
Na₂SO₄: Sodium sulphate
NaHSO₄: Sodium sulphate
Na₂S: Sodium sulphite
The symbol Cl− represents
A chlorine atom
A chlorine molecule
A chloride ion
A chlorate radical
The valency of nitrogen in NH₃ is
1
2
3
4
The element with atomic number 20 has configuration
2,8,8,2
2,8,10
2,8,2
2,18
What is the charge on the phosphate ion?
-1
-2
-3
+3
Which of the following correctly represents zinc chloride?
ZnCl
ZnCl₂
Zn₂Cl
Zn₂Cl₃
The radical NO₃− is known as
Nitrite
Nitrate
Nitride
Nitrogen oxide
What is the name of the compound NaOH?
Sodium oxide
Sodium hydroxide
Sodium hydrogen oxide
Sodium hydrate
Which of the following is ammonium ion?
NH₄+
CO₃²⁻
SO₄²⁻
NO₂−
The correct formula for calcium trioxocarbonate(IV) is
CaCO₃
Ca(CO₃)2
CaC₃O₃
Ca₂CO₃
What is the electronic configuration of a chloride ion?
2,8,7
2,8,8
2,7
2,8,6
Which of the following represents a radical?
CO₃²⁻
Na+
Cl₂
Fe³⁺
The IUPAC name of CuSO₄ is
Copper(II) sulphate
Copper sulphite
Copper(IV) sulphate
Cuprous sulphate
Which of the following has a valency of 2?
Sodium
Calcium
Aluminium
Potassium
The formula of the hydroxide radical is
OH−
HO₂−
H₂O
O₂−
What is the valency of phosphorus in PCl₃?
1
2
3
5
The element with electronic configuration 2,8,1 is
Sodium
Magnesium
Aluminium
Potassium
Which of the following is a compound ion?
OH−
Cl−
Na+
O₂−
The IUPAC name for H₂SO₄ is
Sulphuric acid
Hydrogen sulphate
Sulphurous acid
Hydrogen tetraoxosulphate(VI)
The element whose configuration ends with 3p₅ is
H
N
O
Na
What is the valency of magnesium in MgCl₂?
1
2
3
4
Which of the following ions is trivalent?
Al₃+
Mg₂+
Ca₂+
K+
The correct name for NaHCO₃ is
Sodium trioxocarbonate(IV)
Sodium hydrogencarbonate
Sodium carbonate
Sodium bicarbonate
Which of the following has 18 electrons?
Ar
K+
Cl−
All of the above
The ion Fe₂+ is known as
Ferric ion
Ferrous ion
Iron(III) ion
Iron peroxide
The IUPAC name of Na₂SO₄ is
Sodium sulphate
Disodium sulphate
Sodium sulphite
Sodium hydrogen sulphate
What is the valency of chlorine in HClO₃?
1
3
5
7
Which of these is a monatomic ion?
NH₄+
Na+
SO₄²⁻
CO₃²⁻
(WAEC 2021)
Write the electronic configurations of the following elements:
(i) Sodium (Na)
(ii) Magnesium (Mg)
(iii) Sulphur (S)
(WAEC 2022)
(a) Define valency.
(b) State the valency of chlorine, calcium, and aluminium.
(WAEC 2018)
Name the compounds with the following formulae:
(i) NaOH
(ii) CuSO₄
(iii) NH₄Cl
(WAEC 2017)
Determine the oxidation number of sulphur in:
(i) H₂SO₄
(ii) SO₂
(WAEC 2020)
(a) Define a radical.
(b) Give two examples of radicals and their charges.
(WAEC 2019)
Write the formulae of the following compounds:
(i) Calcium trioxocarbonate(IV)
(ii) Sodium tetraoxosulphate(VI)
(iii) Aluminium trichloride
