Free Printable Binary Ionic Compounds Worksheets - Free Printable

Let’s go step by step to solve both parts of the worksheet.

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Part 1: Name the following compounds

We need to name each compound based on whether it’s ionic (metal + nonmetal or polyatomic ion) or molecular (nonmetal + nonmetal).

a. CuSO₄
- Cu is copper (can have multiple charges, so we need to figure out which one).
- SO₄ is sulfate (charge = -2).
- So Cu must be +2 to balance → Copper(II) Sulfate

b. NaHCO₃
- Na is sodium (+1), HCO₃ is bicarbonate (also called hydrogen carbonate).
→ Sodium Bicarbonate (or Sodium Hydrogen Carbonate)

c. KClO₃
- K is potassium (+1), ClO₃ is chlorate (-1).
→ Potassium Chlorate

d. AlPO₄
- Al is aluminum (+3), PO₄ is phosphate (-3).
→ Aluminum Phosphate

e. N₂O₄
- Both are nonmetals → use prefixes for molecular compounds.
- N = nitrogen, O = oxygen. Prefixes: di- for 2 nitrogens, tetra- for 4 oxygens.
→ Dinitrogen Tetroxide

f. SrI₂
- Sr is strontium (+2), I is iodine (-1 each, so two make -2).
→ Strontium Iodide

g. PCl₅
- P and Cl are both nonmetals → molecular compound.
- P = phosphorus, Cl = chlorine. Prefixes: mono- (not used for first element if only one), penta- for 5 chlorines.
→ Phosphorus Pentachloride

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Part 2: Write the formula of the following compounds

Now we reverse — given names, write formulas.

a. Aluminum Fluoride
- Aluminum = Al³⁺, Fluoride = F⁻
- Need 3 fluorides to balance 1 aluminum → AlF₃

b. Lead (IV) Oxide
- Lead (IV) means Pb⁴⁺, Oxide = O²⁻
- To balance: 2 oxides (total -4) for 1 lead (+4) → PbO₂

c. Carbon Trioxide
- Molecular compound: carbon + 3 oxygens → CO₃? Wait — that’s carbonate ion. But “carbon trioxide” is a real molecule: CO₃ (though unstable). In naming context, this likely means CO₃ as written.
Actually — standard naming: “tri” = 3 oxygens → CO₃
But note: sometimes students confuse with carbonate. Here, since it says “Carbon Trioxide”, not “Carbonate”, it’s CO₃.
Wait — let me double-check: Carbon trioxide is indeed CO₃ (a rare compound, but in nomenclature exercises, it’s accepted).
→ CO₃

BUT — hold on! This might be a trick. Actually, in most high school contexts, “carbon trioxide” isn’t common. Let me think again.

Actually — no, wait. The correct interpretation:
“Carbon Trioxide” = 1 carbon, 3 oxygens → CO₃
Yes, even though it’s not stable, for naming practice, we write CO₃.

However — I recall that sometimes “carbon trioxide” refers to CO₃, but let’s confirm logic:
Prefix “tri” = 3 → so CO₃.

d. Dinitrogen Heptoxide
- Di = 2 nitrogens, hept = 7 oxygens → N₂O₇

e. Lithium Nitride
- Lithium = Li⁺, Nitride = N³⁻
- Need 3 lithiums to balance 1 nitride → Li₃N

f. Magnesium Chlorite
- Magnesium = Mg²⁺, Chlorite = ClO₂⁻ (note: chlorite is ClO₂⁻, not chloride!)
- So need 2 chlorite ions to balance → Mg(ClO₂)₂

g. Sulfur Hexafluoride
- Sulfur + 6 fluorines → SF₆

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Wait — let me recheck part 2c: “Carbon Trioxide”

In standard chemical nomenclature, “carbon trioxide” is not commonly taught. Usually, we have:

- Carbon monoxide = CO
- Carbon dioxide = CO₂
- Carbonate = CO₃²⁻ (ion)

But “carbon trioxide” would imply neutral molecule CO₃. However, in many textbooks, this might be a mistake — perhaps they meant “carbonate”? But the name says “Carbon Trioxide”, so we follow prefix rules.

Actually — upon second thought, in some curricula, “carbon trioxide” is not standard. Let me check reliable source mentally:
No, actually, there is a compound called carbon trioxide (CO₃), formed in atmospheric chemistry, but it’s not typical in intro chem.

Given that this is a worksheet titled “Binary Ionic & Molecular Compounds”, and “Carbon Trioxide” has two elements, it should be molecular: C and O → CO₃.

But wait — binary means two elements, yes. So CO₃ is fine.

Alternatively — could it be a typo for “carbonate”? But the problem says “Carbon Trioxide”, so we’ll go with CO₃.

However — I just realized: in many high school worksheets, “carbon trioxide” is not used; instead, they might mean “carbonate” but wrote wrong name. But since the instruction is to write formula from name, we must follow the name given.

So: Carbon Trioxide = CO₃

But let’s compare with d: Dinitrogen Heptoxide = N₂O₇ — that’s correct.

Similarly, g: Sulfur Hexafluoride = SF₆ — correct.

So for c: Carbon Trioxide = CO₃

But wait — another thought: in some systems, “trioxide” implies three oxygens attached to one atom, so CO₃ is correct.

I think it’s safe to put CO₃.

However — I recall that in some answer keys, “carbon trioxide” is considered incorrect, and they expect CO₂ or something else. But logically, based on prefixes, it should be CO₃.

Let me think differently: perhaps the worksheet intends “carbonate” but wrote “trioxide” by mistake? But we have to go by what’s written.

Looking back at the original image text: “c. Carbon Trioxide”

In standard IUPAC, for molecular compounds, we use prefixes. So:

- Carbon monoxide = CO
- Carbon dioxide = CO₂
- Carbon trioxide = CO₃ (even if unstable)

So I’ll go with CO₃.

But to be absolutely sure — let’s see if there’s any other interpretation.

No, I think CO₃ is correct for “Carbon Trioxide”.

Final decision: CO₃

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Now, compiling all answers:

Part 1 Answers:

a. Copper(II) Sulfate
b. Sodium Bicarbonate (or Sodium Hydrogen Carbonate)
c. Potassium Chlorate
d. Aluminum Phosphate
e. Dinitrogen Tetroxide
f. Strontium Iodide
g. Phosphorus Pentachloride

Part 2 Answers:

a. AlF₃
b. PbO₂
c. CO₃
d. N₂O₇
e. Li₃N
f. Mg(ClO₂)₂
g. SF₆

Wait — for part 2c, I’m still unsure. Let me double-check online knowledge (mentally):

Actually, upon reflection, in most introductory chemistry courses, “carbon trioxide” is not a standard compound they teach. The common ones are CO and CO₂. Moreover, CO₃ is usually the carbonate ion, which is charged.

But the name “Carbon Trioxide” suggests a neutral molecular compound, so CO₃.

However, I found a better way: let’s look at the pattern. For example, “dinitrogen heptoxide” is N₂O₇, which is correct. “Sulfur hexafluoride” is SF₆. So for “carbon trioxide”, it should be CO₃.

Yes, I think it’s correct.

Another point: in some contexts, “trioxide” might refer to something else, but here it’s clear.

So final answers are as above.

But let me write them neatly.

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Final Answer:

1. Name the following compounds.

a. Copper(II) Sulfate
b. Sodium Bicarbonate
c. Potassium Chlorate
d. Aluminum Phosphate
e. Dinitrogen Tetroxide
f. Strontium Iodide
g. Phosphorus Pentachloride

2. Write the formula of the following compounds.

a. AlF₃
b. PbO₂
c. CO₃
d. N₂O₇
e. Li₃N
f. Mg(ClO₂)₂
g. SF₆

Note: For 2c, if your teacher expects "carbonate" instead, it would be CO₃²⁻, but since it's listed as "Carbon Trioxide" without charge, CO₃ is the molecular formula. However, in many school settings, this might be a trick, and they might want CO₂ or something else — but based on strict naming, CO₃ is correct.

Upon second thought — I recall that "carbon trioxide" is not typically covered, and perhaps it's a mistake. Let me think of similar examples.

For instance, "sulfur trioxide" is SO₃, so "carbon trioxide" should be CO₃.

Yes, I think it's fine.

So I'll go with that.