Chemical Economics-formula Revision Questions
1.
A.
B.
C.
D.
The correct formula for sulphur trioxide is
SO
SO2
SO3
SO4
2.
A.
B.
C.
D.
In the compound MnO2, manganese has a valency of
4
3
2
1
3. Which of the following pairs of elements would form a compound with a formula
of the type X2Y3? Where X is a metal and Y is a non-metal
A
B
C
D
X
potassium
calcium
magnesium
aluminium
Y
chlorine
oxygen
nitrogen
sulphur
4. A compound has a formula of the type XY2. Where X is a metal and Y is a nonmetal. The valencies of X and Y must be
A
B
C
D
Valency of X
1
2
3
2
Valency of Y
2
1
2
3
5. The formula mass of the compound sulphur tetrafluoride is
A. 51
B. 70
C. 108
D. 127
Section B
FORMULAE AND EQUATIONS
1. Write formulae for the following elements:
carbon
calcium
hydrogen
lithium
oxygen
nitrogen
copper
chlorine
helium
iodine
2. Write formulae for the following compounds:
carbon dioxide
sulphur trioxide
carbon monoxide
nitrogen dioxide
silicon tetrafluoride
nitrogen monoxide
carbon tetrafluoride
dinitrogen tetroxide
3. Write formulae for the following compounds. Also indicate whether they have
ionic or covalent bonding by entering “I” or “C” in the RH column
FORMULA
IONIC OR
COVALENT?
potassium iodide
zinc (II) oxide
silicon oxide
carbon monoxide
lead (II) bromide
carbon tetrachloride
iron (III) hydroxide
sulphur trioxide
phosphorus pentachloride
sodium oxide
nitrogen hydride
copper (II) chloride
sulphur dioxide
4. Write formulae for the following compounds:
sulphuric acid
nitric acid
hydrochloric acid
sodium hydroxide
potassium hydroxide
calcium hydroxide
5. List the seven diatomic elements.
THE MOLE
1. Calculate the formula mass for each substance:
CO2
MgCl2
C2H6
CaSO4
Br2
aluminium oxide
hydrogen
potassium oxide
sulphur dioxide