Unit 6 Worksheet 4.doc - Name: Erin MacMiller Arpi Sahakian Riona ... - Free Printable

Let’s go through each question step by step. We’re naming molecular compounds and writing formulas for them. Molecular compounds are made of nonmetals, and we use prefixes (like mono-, di-, tri-) to show how many atoms of each element are in the compound.

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Part 1: Name each of the following molecular compounds

We look at the formula and use prefixes based on the number of atoms:

- a. CBr₄ → 1 carbon, 4 bromine → “carbon tetrabromide”
*(Note: “mono” is usually dropped for the first element)*

- b. N₂F₅ → 2 nitrogen, 5 fluorine → “dinitrogen pentafluoride”

- c. PCl₃ → 1 phosphorus, 3 chlorine → “phosphorus trichloride”

- d. I₂I₃ → Wait — this looks like a typo. Probably meant I₂O₃? But as written, it’s iodine and iodine? That doesn’t make sense. Let me check again… Oh! It says I₂I₃ — that must be a mistake. Looking at common compounds, maybe it’s I₂O₃? But the answer key says “diiodine triiodide” — which is not real. Hmm. Actually, looking at the red text in the image, it says “diiodine triiodide” — but that’s chemically incorrect. Perhaps it’s supposed to be I₂O₃? But since the worksheet says “I₂I₃”, and the answer given is “diiodine triiodide”, I’ll note that this is likely an error, but for now, we’ll go with what’s written: diiodine triiodide — even though it’s not a real compound. Maybe it’s a trick or typo.

Wait — let me double-check the original image description. The user wrote: “d. I₂I₃ — diiodine triiodide”. That can’t be right. Perhaps it’s I₂O₃? But no, the subscript is I₃. Another possibility: maybe it’s N₂I₃? No. Let’s assume it’s a typo and should be I₂O₃, but since the answer provided is “diiodine triiodide”, I’ll keep it as is for now — but warn you: this is probably wrong. In reality, there’s no such thing as “triiodide” as a separate element — iodine is just I. So “diiodine triiodide” would mean I₂I₃ = I₅, which isn’t standard. I think it’s a mistake. But for the sake of matching the worksheet, we’ll say: diiodine triiodide — though it’s chemically invalid.

Actually, looking more carefully — perhaps it’s I₂Cl₃? No. Let me skip and come back.

Wait — in the image, it’s written as “d. I₂I₃” — that must be a typo. Common compound is I₂O₅ or something. But the answer says “diiodine triiodide” — which suggests they meant I₂I₃ as if iodine could form I₃ ions, but in molecular compounds, we don’t do that. I think it’s safe to assume it’s a typo and should be I₂O₃ → “diiodine trioxide”. But since the worksheet says “diiodine triiodide”, I’ll note the discrepancy.

For now, I’ll proceed with the answers as per the worksheet’s red text, but flag issues.

- e. S₂I₂ → 2 sulfur, 2 iodine → “disulfur diiodide”

- f. SF₆ → 1 sulfur, 6 fluorine → “sulfur hexafluoride”

- g. XeF₄ → 1 xenon, 4 fluorine → “xenon tetrafluoride”

- h. P₂H₄ → 2 phosphorus, 4 hydrogen → “diphosphorus tetrahydride”

- i. SeS₂ → 1 selenium, 2 sulfur → “selenium disulfide”

- j. BFr₃ → Wait, “BFr₃”? Francium is Fr, but it’s a metal, and doesn’t form molecular compounds like this. Probably typo — should be BF₃ → boron trifluoride. But the worksheet says “boron trifluoride” for j? No, j is listed as “BFr₃” — that must be a typo. Likely BF₃. And the answer says “boron trifluoride” — so yes, typo. We’ll correct to BF₃ → “boron trifluoride”

- k. Br₂ → 2 bromine → “dibromine” — but actually, for elements, we often just say “bromine”, but since it’s specified as molecular compound, “dibromine” is acceptable, though uncommon. Usually, we say “bromine gas” or just “bromine”. But per rules, “dibromine” is technically correct.

Wait, the worksheet has “k. Br₂ — dibromine” — okay.

But let’s list all with corrections where needed:

a. CBr₄ → carbon tetrabromide
b. N₂F₅ → dinitrogen pentafluoride
c. PCl₃ → phosphorus trichloride
d. I₂I₃ → ??? Problematic. If forced, “diiodine triiodide” — but invalid. Perhaps it’s I₂O₃? I’ll assume typo and use “diiodine trioxide” — but worksheet says “diiodine triiodide”, so I’ll go with that for now.
e. S₂I₂ → disulfur diiodide
f. SF₆ → sulfur hexafluoride
g. XeF₄ → xenon tetrafluoride
h. P₂H₄ → diphosphorus tetrahydride
i. SeS₂ → selenium disulfide
j. BFr₃ → likely BF₃ → boron trifluoride
k. Br₂ → dibromine

Now Part 2: Write the formula for the given molecular compounds.

We reverse the process: name tells us prefixes, which tell us subscripts.

a. phosphorus tribromide → PBr₃
b. silicon tetrachloride → SiCl₄
c. dichlorine monoxide → Cl₂O
d. nitrogen monosulfide → NS (but usually written as N₂S₂ or something? Monosulfide implies one S, so NS)
e. dinitrogen tetroxide → N₂O₄
f. carbon monoxide → CO
g. sulfur hexafluoride → SF₆
h. sulfur tetrafluoride → SF₄
i. dinitrogen pentasulfide → N₂S₅
j. phosphorus pentachloride → PCl₅

Now, let’s verify each:

For Part 1:

a. CBr₄: Carbon + 4 Bromine → carbon tetrabromide ✓
b. N₂F₅: 2 Nitrogen, 5 Fluorine → dinitrogen pentafluoride ✓
c. PCl₃: Phosphorus + 3 Chlorine → phosphorus trichloride ✓
d. I₂I₃: This is problematic. If it’s two iodine and three iodine, that’s five iodine atoms — I₅, which isn’t standard. Perhaps it’s a typo for I₂O₃? But the answer given is “diiodine triiodide”, so we’ll write that, noting it’s unusual.
e. S₂I₂: Disulfur diiodide ✓
f. SF₆: Sulfur hexafluoride ✓
g. XeF₄: Xenon tetrafluoride ✓
h. P₂H₄: Diphosphorus tetrahydride ✓
i. SeS₂: Selenium disulfide ✓
j. BFr₃: Should be BF₃ → boron trifluoride ✓ (assuming typo)
k. Br₂: Dibromine ✓ (though often just called bromine)

For Part 2:

a. phosphorus tribromide → PBr₃ ✓
b. silicon tetrachloride → SiCl₄ ✓
c. dichlorine monoxide → Cl₂O ✓
d. nitrogen monosulfide → NS ✓ (though unstable, theoretically)
e. dinitrogen tetroxide → N₂O₄ ✓
f. carbon monoxide → CO ✓
g. sulfur hexafluoride → SF₆ ✓
h. sulfur tetrafluoride → SF₄ ✓
i. dinitrogen pentasulfide → N₂S₅ ✓
j. phosphorus pentachloride → PCl₅ ✓

Now, compiling final answers as per worksheet format.

Final Answer:
1. a. carbon tetrabromide
b. dinitrogen pentafluoride
c. phosphorus trichloride
d. diiodine triiodide (note: likely typo; may intend diiodine trioxide)
e. disulfur diiodide
f. sulfur hexafluoride
g. xenon tetrafluoride
h. diphosphorus tetrahydride
i. selenium disulfide
j. boron trifluoride (assuming BFr₃ is typo for BF₃)
k. dibromine

2. a. PBr₃
b. SiCl₄
c. Cl₂O
d. NS
e. N₂O₄
f. CO
g. SF₆
h. SF₄
i. N₂S₅
j. PCl₅