Grade 9 Predicting Products Of Chemical Reactions Worksheets 2024 - Free Printable

Let’s go through each reaction one by one. These are all synthesis (combination) reactions — two elements combine to form a compound. We need to predict the product in words, based on how these elements typically bond.

We’ll use common charges for ions:
- Metals lose electrons → positive ions (cations)
- Nonmetals gain electrons → negative ions (anions)
- Compounds must be neutral (total charge = 0)

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1. barium + oxygen →

Barium is Ba²⁺, Oxygen is O²⁻
They combine 1:1 → barium oxide

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2. magnesium + sulfur →

Magnesium is Mg²⁺, Sulfur is S²⁻
Combine 1:1 → magnesium sulfide

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3. fluorine + calcium →

Fluorine is F⁻, Calcium is Ca²⁺
Need 2 F⁻ to balance 1 Ca²⁺ → calcium fluoride

*(Note: order doesn’t matter — “fluorine + calcium” still makes calcium fluoride)*

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4. potassium + iodine →

Potassium is K⁺, Iodine is I⁻
Combine 1:1 → potassium iodide

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5. aluminum + phosphorus →

Aluminum is Al³⁺, Phosphorus is P³⁻
Combine 1:1 → aluminum phosphide

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6. bromine + sodium →

Bromine is Br⁻, Sodium is Na⁺
Combine 1:1 → sodium bromide

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7. gallium + chlorine →

Gallium is usually Ga³⁺, Chlorine is Cl⁻
Need 3 Cl⁻ to balance 1 Ga³⁺ → gallium chloride

*(Sometimes written as gallium trichloride, but “gallium chloride” is acceptable at this level)*

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8. lithium + nitrogen →

Lithium is Li⁺, Nitrogen is N³⁻
Need 3 Li⁺ to balance 1 N³⁻ → lithium nitride

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9. oxygen + strontium →

Oxygen is O²⁻, Strontium is Sr²⁺
Combine 1:1 → strontium oxide

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10. sodium + phosphorus →

Sodium is Na⁺, Phosphorus is P³⁻
Need 3 Na⁺ to balance 1 P³⁻ → sodium phosphide

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11. silver + iodine →

Silver is usually Ag⁺, Iodine is I⁻
Combine 1:1 → silver iodide

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12. zinc + nitrogen →

Zinc is Zn²⁺, Nitrogen is N³⁻
To balance: LCM of 2 and 3 is 6 → 3 Zn²⁺ and 2 N³⁻ → zinc nitride

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13. potassium chloride →

This one is different — it’s not two elements reacting. It says “potassium chloride →”, which suggests decomposition. But the worksheet title says “Predicting Products - S/D” — likely meaning Synthesis/Decomposition.

Since it’s only one compound listed, and arrow points right, it’s probably asking what happens if you break it down? But potassium chloride is very stable — it doesn’t easily decompose.

Wait — maybe it’s a typo or misformat? Looking back at the pattern, #1–12 are element + element → ?, so #13 might be meant to be “potassium + chlorine →”? That would make sense.

But as written: “potassium chloride →” — if we assume decomposition, products would be potassium metal and chlorine gas.

However, since the directions say “predict the products for each of the following reactions”, and previous ones are synthesis, perhaps this is an error. But let’s follow what’s written.

If potassium chloride breaks apart:
→ potassium + chlorine

But that’s unusual. Alternatively, maybe it’s meant to be “potassium + chlorine → potassium chloride” — but that’s already the reactant side.

Given the context, I think it’s safest to assume it’s a decomposition reaction:

potassium chloride → potassium + chlorine

But note: in reality, this requires electrolysis and isn’t spontaneous. However, for prediction purposes in class, we often write the elements.

Alternatively, if it’s a mistake and should be “potassium + chlorine →”, then answer is “potassium chloride”.

Looking at the numbering — 13 items, first 12 are element+element, last one is compound alone. Likely intended to be decomposition.

I’ll go with decomposition:

→ potassium + chlorine

But wait — chlorine is diatomic! So it should be “chlorine gas” or just “chlorine” — in word equations, we usually say “chlorine”.

Actually, in most school worksheets, they accept “chlorine” even though it’s Cl₂.

So final decision:

For #13: potassium + chlorine

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Now, compiling all answers:

Final Answer:
1. barium oxide
2. magnesium sulfide
3. calcium fluoride
4. potassium iodide
5. aluminum phosphide
6. sodium bromide
7. gallium chloride
8. lithium nitride
9. strontium oxide
10. sodium phosphide
11. silver iodide
12. zinc nitride
13. potassium + chlorine