Question

writing names
writing names is also straightforward. you use the appropriate
of that element.
steps

1. determine the appropriate prefix for each element.
2. write the prefix and the name of the element.

example 3 - n₂o
practice questions
a. n₂o₄
b. so₂
c. h₂o
practice
write the formulas for the following compounds.
a. carbon dioxide
b. diphosphorus trisulphide
c. silicon dioxide
d. dinitrogen monoxide
e. water
f. dichlorine monoxide
g. carbon disulphide
h. bromine gas
i. sulphur trioxide
j. carbon monoxide
k. carbon tetrachloride
l. xenon tetrafluoride
m. sulphur dioxide
n. neon gas
o. dinitrogen tetroxide
p. silicon tetrahydride
q. nitrogen monoxide
r. iodine heptachloride
s. arsenic tribromide
t. krypton difluoride
write the names
a. cf₄
b. nf₃
c. nh₃
d. p₂s₅
e. pbr₃
f. pf₅
g. f₂ gas
h. icl
i. cs₂
j. secl₂
k. co
l. cl₂o
m. sic
n. asbr₃
o. n₂o₄
p. h₂s
q. p₂o₅
r. b₂h₆
s. sf₄
t. tec

Explanation:

Step1: Recall naming rules for covalent compounds

Prefixes are used to indicate the number of atoms of each element.

Step2: Write formulas for given names

a. Carbon dioxide has 1 carbon and 2 oxygen atoms, so formula is $CO_2$.
b. Diphosphorus trisulphide has 2 phosphorus and 3 sulphur atoms, formula is $P_2S_3$.
c. Silicon dioxide has 1 silicon and 2 oxygen atoms, formula is $SiO_2$.
d. Dinitrogen monoxide has 2 nitrogen and 1 oxygen atom, formula is $N_2O$.
e. Water has 2 hydrogen and 1 oxygen atom, formula is $H_2O$.
f. Dichlorine monoxide has 2 chlorine and 1 oxygen atom, formula is $Cl_2O$.
g. Carbon disulphide has 1 carbon and 2 sulphur atoms, formula is $CS_2$.
h. Bromine gas is $Br_2$.
i. Sulphur trioxide has 1 sulphur and 3 oxygen atoms, formula is $SO_3$.
j. Carbon monoxide has 1 carbon and 1 oxygen atom, formula is $CO$.
k. Carbon tetrachloride has 1 carbon and 4 chlorine atoms, formula is $CCl_4$.
l. Xenon tetrafluoride has 1 xenon and 4 fluorine atoms, formula is $XeF_4$.
m. Sulphur dioxide has 1 sulphur and 2 oxygen atoms, formula is $SO_2$.
n. Neon gas is $Ne$.
o. Dinitrogen tetroxide has 2 nitrogen and 4 oxygen atoms, formula is $N_2O_4$.
p. Silicon tetrahydride has 1 silicon and 4 hydrogen atoms, formula is $SiH_4$.
q. Nitrogen monoxide has 1 nitrogen and 1 oxygen atom, formula is $NO$.
r. Iodine heptachloride has 1 iodine and 7 chlorine atoms, formula is $ICl_7$.
s. Arsenic tribromide has 1 arsenic and 3 bromine atoms, formula is $AsBr_3$.
t. Krypton difluoride has 1 krypton and 2 fluorine atoms, formula is $KrF_2$.

Answer:

a. $CO_2$
b. $P_2S_3$
c. $SiO_2$
d. $N_2O$
e. $H_2O$
f. $Cl_2O$
g. $CS_2$
h. $Br_2$
i. $SO_3$
j. $CO$
k. $CCl_4$
l. $XeF_4$
m. $SO_2$
n. $Ne$
o. $N_2O_4$
p. $SiH_4$
q. $NO$
r. $ICl_7$
s. $AsBr_3$
t. $KrF_2$