Question

1. examine the prefixes in model 2 below. fill in the numerical value that corresponds to each prefix.

model 2 - prefixes and suffixes
prefix numerical value
mono-
di-
tri-
tetra-
penta-
hexa-
hepta-
octa-
non-
deca-
molecular formula name of compound
bcl₃ boron trichloride
sf₆ sulfur hexafluoride
if₇ iodine heptafluoride
ni₃ nitrogen triiodide
n₂o₄ dinitrogen tetroxide
cl₂o dichlorine monoxide
p₄o₁₀ tetraphosphorus decoxide
b₅h₉ pentaboron nonahydride
br₃o₈ tribromine octoxide
clf chlorine monofluoride

1. what ending do all the compound names have in common?
2. when is a prefix not used in front of the name of the first element?
3. use the prefixes to name each of the following compounds:

molecular formula molecule name
pbr₃
scl₄
n₂f₂
so₃
brf

1. use the names to write the formula for each of the compounds below:

molecular formula molecule name
disulfur decafluoride
carbon tetrachloride
oxygen difluoride
dinitrogen trioxide
tetraphosphorus heptasulfide

Explanation:

1. The prefix "mono -" corresponds to 1, "di -" to 2, "tri -" to 3, "tetra -" to 4, "penta -" to 5, "hexa -" to 6, "hepta -" to 7, "octa -" to 8, "nona -" to 9, "deca -" to 10.
2. All compound names end with -ide.
3. A prefix is not used in front of the name of the first element when there is only one atom of that element in the compound.

9)

• $PBr_3$: Phosphorus tribromide
• $SCl_4$: Sulfur tetrachloride
• $N_2F_2$: Dinitrogen difluoride
• $SO_3$: Sulfur trioxide
• $BrF$: Bromine monofluoride

10)

• Disulfur decafluoride: $S_2F_{10}$
• Carbon tetrachloride: $CCl_4$
• Oxygen difluoride: $OF_2$
• Dinitrogen trioxide: $N_2O_3$
• Tetraphosphorus heptasulfide: $P_4S_7$

Answer:

1. mono -: 1, di -: 2, tri -: 3, tetra -: 4, penta -: 5, hexa -: 6, hepta -: 7, octa -: 8, nona -: 9, deca -: 10
2. -ide
3. When there is only one atom of the first - named element.
4. Phosphorus tribromide, Sulfur tetrachloride, Dinitrogen difluoride, Sulfur trioxide, Bromine monofluoride
5. $S_2F_{10}$, $CCl_4$, $OF_2$, $N_2O_3$, $P_4S_7$