1. Aim # 3: How can we determine the formula of a molecular compound from its name?
H.W. # 3
Study pp
Ans. ques. p. 108 # 10,11
p. 111 # 49
Do Now: Name the following compounds
Cu(NO3)2 NH4Br Pb(SO4) Hg2(NO3)2
Write formulas for the following compounds
zinc nitrate sodium sulfate hydrogen sulfide
ammonium thiocyanate potassium permanganate

2. I Naming binary molecular compounds (Type III binary compounds)
Prefixes are used to indicate the number of atoms
of each element in the molecule.
mon(o) - 1 hex(a)
di hept(a)- 7
tri oct(a)
tetr(a) non(a) - 9
pent(a) dec(a) - 10
e.g. dinitrogen trioxide N2O3

3. Now you try it. dinitrogen monoxide tetraphosphorous hexoxide
dinitrogen pentasulfide
dihydrogen monoxide

4. carbon tetrachloride CCl4 Now you try it. phosphorous trichloride
Note: for the first element in the compound, the prefix “mon(o)” is not used- we simply use the name of the element.
e.g. sulfur dioxide SO2
carbon tetrachloride CCl4
Now you try it.
phosphorous trichloride
carbon disulfide
oxygen diflouride

5. II Writing names from formulas
WORK BACKWARDS!
Don’t forget- the last element ends in “ide”.
Name the following compounds:
PCl5 S4N2
OF2 SeO2
N2S3

6. Review:
What is the correct formula for ammonium carbonate?
1) NH4(CO3) ) (NH4)2(CO3)2
2) NH4CO ) (NH4)2CO3
2. What is the total number of atoms in one molecule of (NH4)2SO4?
1) ) ) ) 15

7. 4. Which formula is correctly paired with its name?
3. Which formula is an empirical formula? 1) K2O 2) H2O ) C2H ) C6H6
4. Which formula is correctly paired with its
name?
1) MgCl magnesium chlorine
2) K2O phosphorous dioxide
3) CuCl copper (II) chloride
4) FeO iron (IV) oxide

8. 5. Elements fro groups 15 and 16 will combine to form a compound with the general formula ) M2N ) MN ) M2N ) M2N