1. Fill in the table to indicate the number of atoms of each type in the molecular formula:
- ClF: 1, 1
- ClF₅: 1, 5
- CO: 1, 1
- CO₂: 1, 2
- Cl₂O: 2, 1
- PCl₅: 1, 5
- N₂O₅: 2, 5
2. Examine the molecular formulas given in Model 1 for various molecular compounds.
a. How many different elements are present in each compound shown?
Two
b. Do the compounds combine metals with metals, metals with nonmetals, or nonmetals with nonmetals?
Non-metals with non-metals
c. Based on your answer to b, what type of bonding must be involved in molecular compounds?
Covalent bonds
3. Find all the compounds in Model 1 that have chlorine and fluorine in them. Explain why the name “chlorine fluoride” is not sufficient to identify a specific compound.
The number of fluorine atoms is different in the two compounds, but name does not reflect the difference.
4. Assuming that the name of the compound gives a clue to its molecular formula, predict how many atoms each of these prefixes indicates, and provide two examples.
- mono-: 1 atom (e.g., carbon monoxide, chlorine monofluoride)
- di-: 2 atoms (e.g., carbon dioxide, dichlorine monoxide)
- tri-: 3 atoms (e.g., dinitrogen trioxide — not in table, but implied by pattern; phosphorus pentachloride has penta-, so tri- would be 3)
- tetra-: 4 atoms (e.g., carbon tetrachloride — not in table, but implied; silicon tetrafluoride)
- penta-: 5 atoms (e.g., chlorine pentafluoride, phosphorus pentachloride)
Parent Tip: Review the logic above to help your child master the concept of naming molecular formula worksheet.
