Answer key for balancing chemical equations with solutions.
Answer key for balancing chemical equations, listing 20 reactions with balanced formulas and "balanced as" notes.
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Step-by-step solution for: Balancing Chemical Equations Practice Sheet - Worksheets Library
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Show Answer Key & Explanations
Step-by-step solution for: Balancing Chemical Equations Practice Sheet - Worksheets Library
Let’s go through each problem one by one. These are all chemical equations that need to be balanced — meaning the number of atoms of each element must be the same on both sides (left and right) of the arrow.
We’ll check each equation as written in the answer key, verify if it’s correctly balanced, and note any corrections needed.
---
1) Fe₂O₃ + 3H₂ → 2Fe + 3H₂O
Left: Fe=2, O=3, H=6
Right: Fe=2, H=6, O=3 → ✔ Balanced
---
2) CaO + H₂O → Ca(OH)₂
Left: Ca=1, O=2, H=2
Right: Ca=1, O=2, H=2 → ✔ Balanced
*(Note: “balanced in” is probably a typo or leftover from another format — this is already balanced.)*
---
3) 2Na + 2H₂O → 2NaOH + H₂
Left: Na=2, H=4, O=2
Right: Na=2, O=2, H=2+2=4 → ✔ Balanced
---
4) P + 5O₂ → 2P₂O₅? Wait — original says: P + 5O₂ → 2PO₅? That can’t be right.
Wait — looking at the image again:
It says: 4) P + 5O₂ → 2PO₅ — but PO₅ doesn’t exist. Probably meant P₄O₁₀, which is common.
But let’s check what’s written:
If it’s P + 5O₂ → 2PO₅ → Left: P=1, O=10; Right: P=2, O=10 → Not balanced for P.
Actually, standard reaction is: P₄ + 5O₂ → 2P₂O₅ — but here it starts with just “P”.
Looking back at the image — it actually says:
4) P + 5O₂ → 2PO₅ — which is chemically incorrect. But maybe it’s a typo and should be P₄ + 5O₂ → 2P₂O₅?
Wait — no, in the image it’s written as:
> 4) P + 5O₂ → 2PO₅
That’s not correct. Let me recheck the original image text you provided.
You wrote:
> 4) P + 5O₂ → 2PO₅
But that’s impossible because phosphorus pentoxide is P₂O₅, not PO₅.
Actually, looking more carefully — perhaps it’s P₄ + 5O₂ → 2P₂O₅? But the coefficient for P is missing.
Wait — in your list, it says:
> 4) P + 5O₂ → 2PO₅
This must be an error. The correct balanced equation for forming diphosphorus pentoxide is:
P₄ + 5O₂ → 2P₂O₅
But since the problem shows “P”, not “P₄”, we have to assume it’s a mistake. However, in many textbooks, they write it as:
4P + 5O₂ → 2P₂O₅
Let’s test that:
Left: P=4, O=10
Right: P=4, O=10 → ✔ Balanced
So likely, the intended equation is 4P + 5O₂ → 2P₂O₅, but it was miswritten as “P + 5O₂ → 2PO₅”. Since the answer key says nothing about balancing it, and it’s listed as-is, we’ll assume it’s supposed to be 4P + 5O₂ → 2P₂O₅ — but in your list it’s written incorrectly.
However, in your original input, it says:
> 4) P + 5O₂ → 2PO₅
And then next line says “balanced in” — which might mean it’s not balanced? Or maybe it’s a formatting issue.
To avoid confusion, let’s proceed with the assumption that the answer key has typos, and we’ll correct them based on chemistry rules.
But since you asked to solve the problem accurately, I will treat each equation as given and balance it properly if needed.
Let me restart with careful checking of each as written in your list.
---
Actually, looking again at your original message, the "Answer Key" section lists equations with some marked “balanced in” — which probably means those were unbalanced in the original worksheet and now are shown balanced.
But for accuracy, I will verify each one.
Let me go one by one with atom counts.
---
1) Fe₂O₃ + 3H₂ → 2Fe + 3H₂O
Fe: 2 = 2
O: 3 = 3
H: 6 = 6 → ✔ OK
---
2) CaO + H₂O → Ca(OH)₂
Ca: 1=1
O: 1+1=2; right: 2 (from OH twice)
H: 2=2 → ✔ OK
---
3) 2Na + 2H₂O → 2NaOH + H₂
Na: 2=2
H: 4 = 2 (in NaOH) + 2 (in H₂) = 4
O: 2=2 → ✔ OK
---
4) P + 5O₂ → 2PO₅
This is problematic. PO₅ is not a real compound. Phosphorus oxide is usually P₄O₁₀ or P₂O₅.
Assuming it's meant to be P₄ + 5O₂ → 2P₂O₅, but written poorly.
If we take it literally: left P=1, O=10; right P=2, O=10 → not balanced.
Correct version: 4P + 5O₂ → 2P₂O₅
Left: P=4, O=10
Right: P=4, O=10 → ✔
So I'll assume that’s what was intended.
---
5) CaC₂ + 2H₂O → C₂H₂ + Ca(OH)₂
Left: Ca=1, C=2, H=4, O=2
Right: C=2, H=2+2=4, Ca=1, O=2 → ✔ OK
---
6) 2Hg + O₂ → 2HgO
Hg: 2=2
O: 2=2 → ✔ OK
---
7) 2Br + Cl₂ → 2Cl + Br₂
This looks odd. Bromine and chlorine are diatomic.
Probably meant: 2Br⁻ + Cl₂ → 2Cl⁻ + Br₂ (redox), but as written:
Atoms: Br: 2=2, Cl: 2=2 → technically balanced, but chemically unusual without charges.
In context of high school, maybe acceptable as is.
---
8) CaO + H₂ → Ca + H₂O
Left: Ca=1, O=1, H=2
Right: Ca=1, H=2, O=1 → ✔ Balanced
---
9) 4Cr + 3SnCl₄ → 4CrCl₃ + 3Sn
Cr: 4=4
Sn: 3=3
Cl: 12=12 → ✔ OK
---
10) AgNO₃ + NaCl → AgCl + NaNO₃
Ag:1=1, N:1=1, O:3=3, Na:1=1, Cl:1=1 → ✔ Already balanced
---
11) Mg + CuSO₄ → MgSO₄ + Cu
Mg:1=1, Cu:1=1, S:1=1, O:4=4 → ✔ Balanced
---
12) 2Be + C → 2BeC + Be? Wait — original says: 2Be + C → 2BeC + Be
That would be: left Be=2, C=1; right Be=2+1=3, C=2 → not balanced.
Probably typo. Likely meant: 2Be + C → Be₂C
Then: Be:2=2, C:1=1 → ✔
Or if it’s Be + C → BeC, also balanced.
But as written: 2Be + C → 2BeC + Be — that’s invalid.
I think it’s a mistake. Should be 2Be + C → Be₂C
---
13) ZnCO₃ → ZnO + CO₂
Zn:1=1, C:1=1, O:3=1+2=3 → ✔ Balanced
---
14) 2K + 2H₂O → 2KOH + H₂
K:2=2, H:4=2+2=4, O:2=2 → ✔ OK
---
15) 3MgCl₂ + Pb(NO₃)₂ → 3Mg(NO₃)₂ + PbCl₂? Wait — original says:
> 15) 3MgCl₂ + Pb(NO₃)₂ → 3Mg(NO₃)₂ + PbCl₂
Check atoms:
Left: Mg=3, Cl=6, Pb=1, N=2, O=6
Right: Mg=3, N=6, O=18, Pb=1, Cl=2 → NOT balanced!
Big mistake.
Correct should be:
MgCl₂ + Pb(NO₃)₂ → Mg(NO₃)₂ + PbCl₂
Then: Mg:1=1, Cl:2=2, Pb:1=1, N:2=2, O:6=6 → ✔
But with coefficients 3 and 3, it’s wrong.
So the answer key has an error here.
Should be: MgCl₂ + Pb(NO₃)₂ → Mg(NO₃)₂ + PbCl₂
No coefficients needed.
---
16) CaCN₂ + 3H₂O → CaCO₃ + 2NH₃
Left: Ca=1, C=1, N=2, H=6, O=3
Right: Ca=1, C=1, O=3, N=2, H=6 → ✔ OK
---
17) 2Fe(NO₃)₃ + MgF₂ → Fe₂F₆ + 3Mg(NO₃)₂? Original says:
> 17) 2Fe(NO₃)₃ + MgF₂ → Fe₂F₆ + 3Mg(NO₃)₂
Check:
Left: Fe=2, N=6, O=18, Mg=1, F=2
Right: Fe=2, F=6, Mg=3, N=6, O=18 → Mg and F not balanced.
Should be:
2Fe(NO₃)₃ + 3MgF₂ → Fe₂F₆ + 3Mg(NO₃)₂
Then: Fe:2=2, N:6=6, O:18=18, Mg:3=3, F:6=6 → ✔
So answer key missed the 3 before MgF₂.
---
18) NaOH + HCl → H₂O + NaCl
Na:1=1, O:1=1, H:1+1=2=2, Cl:1=1 → ✔ Balanced
---
19) 3AlCl₃ + 3(NH₄)PO₄ → AlPO₄ + 3NH₄Cl? Original:
> 19) 3AlCl₃ + 3(NH₄)₃PO₄ → AlPO₄ + 3NH₄Cl
Left: Al=3, Cl=9, N=9, H=36, P=3, O=12
Right: Al=1, P=1, O=4, N=3, H=12, Cl=3 → Way off.
Correct should be:
AlCl₃ + (NH₄)₃PO₄ → AlPO₄ + 3NH₄Cl
Then: Al:1=1, Cl:3=3, N:3=3, H:12=12, P:1=1, O:4=4 → ✔
So coefficients of 3 are wrong.
---
20) FeS + H₂SO₄ → FeSO₄ + H₂S
Fe:1=1, S:1+1=2=1+1, H:2=2, O:4=4 → ✔ Balanced
---
21) 2Na₂SO₄ + Sr(NO₃)₂ → 2NaNO₃ + SrSO₄? Original:
> 21) 2Na₂SO₄ + Sr(NO₃)₂ → 2NaNO₃ + SrSO₄
Left: Na=4, S=2, O=8+6=14, Sr=1, N=2
Right: Na=2, N=2, O=6+4=10, Sr=1, S=1 → Not balanced.
Correct: Na₂SO₄ + Sr(NO₃)₂ → 2NaNO₃ + SrSO₄
Then: Na:2=2, S:1=1, O:4+6=10=6+4, Sr:1=1, N:2=2 → ✔
So extra 2 on left is wrong.
---
22) Ba(OH)₂ + MgSO₄ → Mg(OH)₂ + BaSO₄
Ba:1=1, O:2+4=6=2+4, H:2=2, Mg:1=1, S:1=1 → ✔ Balanced
---
23) 2Na + 2H₂O → 2NaOH + H₂ — same as #3, already checked ✔
---
24) SnO + 4HF → SnF₄ + 2H₂O
Sn:1=1, O:1=2? Wait — left O=1, right O=2 → not balanced.
Should be: SnO + 4HF → SnF₄ + 2H₂O
Left: Sn=1, O=1, H=4, F=4
Right: Sn=1, F=4, H=4, O=2 → O not balanced.
Mistake.
Correct: SnO₂ + 4HF → SnF₄ + 2H₂O
Then: Sn:1=1, O:2=2, H:4=4, F:4=4 → ✔
So probably typo — should be SnO₂, not SnO.
---
25) CaO + H₂ → Ca + H₂O — same as #8, already balanced ✔
---
Now, summarizing corrections:
Many equations in the "answer key" have errors or typos. For accurate solving, here are the corrected balanced versions where needed:
- #4: Should be 4P + 5O₂ → 2P₂O₅
- #12: Should be 2Be + C → Be₂C (or similar)
- #15: Should be MgCl₂ + Pb(NO₃)₂ → Mg(NO₃)₂ + PbCl₂
- #17: Should be 2Fe(NO₃)₃ + 3MgF₂ → Fe₂F₆ + 3Mg(NO₃)₂
- #19: Should be AlCl₃ + (NH₄)₃PO₄ → AlPO₄ + 3NH₄Cl
- #21: Should be Na₂SO₄ + Sr(NO₃)₂ → 2NaNO₃ + SrSO₄
- #24: Should be SnO₂ + 4HF → SnF₄ + 2H₂O
Others are mostly correct as written.
Since the user asked to "solve the problem accurately", and the problem appears to be verifying or completing these equations, I will provide the fully corrected set.
But to match the format, I'll list each with its correct balanced form.
Final Answer:
Here is the accurate, corrected version of each equation:
1) Fe₂O₃ + 3H₂ → 2Fe + 3H₂O
2) CaO + H₂O → Ca(OH)₂
3) 2Na + 2H₂O → 2NaOH + H₂
4) 4P + 5O₂ → 2P₂O₅
5) CaC₂ + 2H₂O → C₂H₂ + Ca(OH)₂
6) 2Hg + O₂ → 2HgO
7) 2Br + Cl₂ → 2Cl + Br₂ *(note: unusual, but atom-balanced)*
8) CaO + H₂ → Ca + H₂O
9) 4Cr + 3SnCl₄ → 4CrCl₃ + 3Sn
10) AgNO₃ + NaCl → AgCl + NaNO₃
11) Mg + CuSO₄ → MgSO₄ + Cu
12) 2Be + C → Be₂C
13) ZnCO₃ → ZnO + CO₂
14) 2K + 2H₂O → 2KOH + H₂
15) MgCl₂ + Pb(NO₃)₂ → Mg(NO₃)₂ + PbCl₂
16) CaCN₂ + 3H₂O → CaCO₃ + 2NH₃
17) 2Fe(NO₃)₃ + 3MgF₂ → Fe₂F₆ + 3Mg(NO₃)₂
18) NaOH + HCl → H₂O + NaCl
19) AlCl₃ + (NH₄)₃PO₄ → AlPO₄ + 3NH₄Cl
20) FeS + H₂SO₄ → FeSO₄ + H₂S
21) Na₂SO₄ + Sr(NO₃)₂ → 2NaNO₃ + SrSO₄
22) Ba(OH)₂ + MgSO₄ → Mg(OH)₂ + BaSO₄
23) 2Na + 2H₂O → 2NaOH + H₂
24) SnO₂ + 4HF → SnF₄ + 2H₂O
25) CaO + H₂ → Ca + H₂O
All equations are now correctly balanced with proper chemical formulas.
We’ll check each equation as written in the answer key, verify if it’s correctly balanced, and note any corrections needed.
---
1) Fe₂O₃ + 3H₂ → 2Fe + 3H₂O
Left: Fe=2, O=3, H=6
Right: Fe=2, H=6, O=3 → ✔ Balanced
---
2) CaO + H₂O → Ca(OH)₂
Left: Ca=1, O=2, H=2
Right: Ca=1, O=2, H=2 → ✔ Balanced
*(Note: “balanced in” is probably a typo or leftover from another format — this is already balanced.)*
---
3) 2Na + 2H₂O → 2NaOH + H₂
Left: Na=2, H=4, O=2
Right: Na=2, O=2, H=2+2=4 → ✔ Balanced
---
4) P + 5O₂ → 2P₂O₅? Wait — original says: P + 5O₂ → 2PO₅? That can’t be right.
Wait — looking at the image again:
It says: 4) P + 5O₂ → 2PO₅ — but PO₅ doesn’t exist. Probably meant P₄O₁₀, which is common.
But let’s check what’s written:
If it’s P + 5O₂ → 2PO₅ → Left: P=1, O=10; Right: P=2, O=10 → Not balanced for P.
Actually, standard reaction is: P₄ + 5O₂ → 2P₂O₅ — but here it starts with just “P”.
Looking back at the image — it actually says:
4) P + 5O₂ → 2PO₅ — which is chemically incorrect. But maybe it’s a typo and should be P₄ + 5O₂ → 2P₂O₅?
Wait — no, in the image it’s written as:
> 4) P + 5O₂ → 2PO₅
That’s not correct. Let me recheck the original image text you provided.
You wrote:
> 4) P + 5O₂ → 2PO₅
But that’s impossible because phosphorus pentoxide is P₂O₅, not PO₅.
Actually, looking more carefully — perhaps it’s P₄ + 5O₂ → 2P₂O₅? But the coefficient for P is missing.
Wait — in your list, it says:
> 4) P + 5O₂ → 2PO₅
This must be an error. The correct balanced equation for forming diphosphorus pentoxide is:
P₄ + 5O₂ → 2P₂O₅
But since the problem shows “P”, not “P₄”, we have to assume it’s a mistake. However, in many textbooks, they write it as:
4P + 5O₂ → 2P₂O₅
Let’s test that:
Left: P=4, O=10
Right: P=4, O=10 → ✔ Balanced
So likely, the intended equation is 4P + 5O₂ → 2P₂O₅, but it was miswritten as “P + 5O₂ → 2PO₅”. Since the answer key says nothing about balancing it, and it’s listed as-is, we’ll assume it’s supposed to be 4P + 5O₂ → 2P₂O₅ — but in your list it’s written incorrectly.
However, in your original input, it says:
> 4) P + 5O₂ → 2PO₅
And then next line says “balanced in” — which might mean it’s not balanced? Or maybe it’s a formatting issue.
To avoid confusion, let’s proceed with the assumption that the answer key has typos, and we’ll correct them based on chemistry rules.
But since you asked to solve the problem accurately, I will treat each equation as given and balance it properly if needed.
Let me restart with careful checking of each as written in your list.
---
Actually, looking again at your original message, the "Answer Key" section lists equations with some marked “balanced in” — which probably means those were unbalanced in the original worksheet and now are shown balanced.
But for accuracy, I will verify each one.
Let me go one by one with atom counts.
---
1) Fe₂O₃ + 3H₂ → 2Fe + 3H₂O
Fe: 2 = 2
O: 3 = 3
H: 6 = 6 → ✔ OK
---
2) CaO + H₂O → Ca(OH)₂
Ca: 1=1
O: 1+1=2; right: 2 (from OH twice)
H: 2=2 → ✔ OK
---
3) 2Na + 2H₂O → 2NaOH + H₂
Na: 2=2
H: 4 = 2 (in NaOH) + 2 (in H₂) = 4
O: 2=2 → ✔ OK
---
4) P + 5O₂ → 2PO₅
This is problematic. PO₅ is not a real compound. Phosphorus oxide is usually P₄O₁₀ or P₂O₅.
Assuming it's meant to be P₄ + 5O₂ → 2P₂O₅, but written poorly.
If we take it literally: left P=1, O=10; right P=2, O=10 → not balanced.
Correct version: 4P + 5O₂ → 2P₂O₅
Left: P=4, O=10
Right: P=4, O=10 → ✔
So I'll assume that’s what was intended.
---
5) CaC₂ + 2H₂O → C₂H₂ + Ca(OH)₂
Left: Ca=1, C=2, H=4, O=2
Right: C=2, H=2+2=4, Ca=1, O=2 → ✔ OK
---
6) 2Hg + O₂ → 2HgO
Hg: 2=2
O: 2=2 → ✔ OK
---
7) 2Br + Cl₂ → 2Cl + Br₂
This looks odd. Bromine and chlorine are diatomic.
Probably meant: 2Br⁻ + Cl₂ → 2Cl⁻ + Br₂ (redox), but as written:
Atoms: Br: 2=2, Cl: 2=2 → technically balanced, but chemically unusual without charges.
In context of high school, maybe acceptable as is.
---
8) CaO + H₂ → Ca + H₂O
Left: Ca=1, O=1, H=2
Right: Ca=1, H=2, O=1 → ✔ Balanced
---
9) 4Cr + 3SnCl₄ → 4CrCl₃ + 3Sn
Cr: 4=4
Sn: 3=3
Cl: 12=12 → ✔ OK
---
10) AgNO₃ + NaCl → AgCl + NaNO₃
Ag:1=1, N:1=1, O:3=3, Na:1=1, Cl:1=1 → ✔ Already balanced
---
11) Mg + CuSO₄ → MgSO₄ + Cu
Mg:1=1, Cu:1=1, S:1=1, O:4=4 → ✔ Balanced
---
12) 2Be + C → 2BeC + Be? Wait — original says: 2Be + C → 2BeC + Be
That would be: left Be=2, C=1; right Be=2+1=3, C=2 → not balanced.
Probably typo. Likely meant: 2Be + C → Be₂C
Then: Be:2=2, C:1=1 → ✔
Or if it’s Be + C → BeC, also balanced.
But as written: 2Be + C → 2BeC + Be — that’s invalid.
I think it’s a mistake. Should be 2Be + C → Be₂C
---
13) ZnCO₃ → ZnO + CO₂
Zn:1=1, C:1=1, O:3=1+2=3 → ✔ Balanced
---
14) 2K + 2H₂O → 2KOH + H₂
K:2=2, H:4=2+2=4, O:2=2 → ✔ OK
---
15) 3MgCl₂ + Pb(NO₃)₂ → 3Mg(NO₃)₂ + PbCl₂? Wait — original says:
> 15) 3MgCl₂ + Pb(NO₃)₂ → 3Mg(NO₃)₂ + PbCl₂
Check atoms:
Left: Mg=3, Cl=6, Pb=1, N=2, O=6
Right: Mg=3, N=6, O=18, Pb=1, Cl=2 → NOT balanced!
Big mistake.
Correct should be:
MgCl₂ + Pb(NO₃)₂ → Mg(NO₃)₂ + PbCl₂
Then: Mg:1=1, Cl:2=2, Pb:1=1, N:2=2, O:6=6 → ✔
But with coefficients 3 and 3, it’s wrong.
So the answer key has an error here.
Should be: MgCl₂ + Pb(NO₃)₂ → Mg(NO₃)₂ + PbCl₂
No coefficients needed.
---
16) CaCN₂ + 3H₂O → CaCO₃ + 2NH₃
Left: Ca=1, C=1, N=2, H=6, O=3
Right: Ca=1, C=1, O=3, N=2, H=6 → ✔ OK
---
17) 2Fe(NO₃)₃ + MgF₂ → Fe₂F₆ + 3Mg(NO₃)₂? Original says:
> 17) 2Fe(NO₃)₃ + MgF₂ → Fe₂F₆ + 3Mg(NO₃)₂
Check:
Left: Fe=2, N=6, O=18, Mg=1, F=2
Right: Fe=2, F=6, Mg=3, N=6, O=18 → Mg and F not balanced.
Should be:
2Fe(NO₃)₃ + 3MgF₂ → Fe₂F₆ + 3Mg(NO₃)₂
Then: Fe:2=2, N:6=6, O:18=18, Mg:3=3, F:6=6 → ✔
So answer key missed the 3 before MgF₂.
---
18) NaOH + HCl → H₂O + NaCl
Na:1=1, O:1=1, H:1+1=2=2, Cl:1=1 → ✔ Balanced
---
19) 3AlCl₃ + 3(NH₄)PO₄ → AlPO₄ + 3NH₄Cl? Original:
> 19) 3AlCl₃ + 3(NH₄)₃PO₄ → AlPO₄ + 3NH₄Cl
Left: Al=3, Cl=9, N=9, H=36, P=3, O=12
Right: Al=1, P=1, O=4, N=3, H=12, Cl=3 → Way off.
Correct should be:
AlCl₃ + (NH₄)₃PO₄ → AlPO₄ + 3NH₄Cl
Then: Al:1=1, Cl:3=3, N:3=3, H:12=12, P:1=1, O:4=4 → ✔
So coefficients of 3 are wrong.
---
20) FeS + H₂SO₄ → FeSO₄ + H₂S
Fe:1=1, S:1+1=2=1+1, H:2=2, O:4=4 → ✔ Balanced
---
21) 2Na₂SO₄ + Sr(NO₃)₂ → 2NaNO₃ + SrSO₄? Original:
> 21) 2Na₂SO₄ + Sr(NO₃)₂ → 2NaNO₃ + SrSO₄
Left: Na=4, S=2, O=8+6=14, Sr=1, N=2
Right: Na=2, N=2, O=6+4=10, Sr=1, S=1 → Not balanced.
Correct: Na₂SO₄ + Sr(NO₃)₂ → 2NaNO₃ + SrSO₄
Then: Na:2=2, S:1=1, O:4+6=10=6+4, Sr:1=1, N:2=2 → ✔
So extra 2 on left is wrong.
---
22) Ba(OH)₂ + MgSO₄ → Mg(OH)₂ + BaSO₄
Ba:1=1, O:2+4=6=2+4, H:2=2, Mg:1=1, S:1=1 → ✔ Balanced
---
23) 2Na + 2H₂O → 2NaOH + H₂ — same as #3, already checked ✔
---
24) SnO + 4HF → SnF₄ + 2H₂O
Sn:1=1, O:1=2? Wait — left O=1, right O=2 → not balanced.
Should be: SnO + 4HF → SnF₄ + 2H₂O
Left: Sn=1, O=1, H=4, F=4
Right: Sn=1, F=4, H=4, O=2 → O not balanced.
Mistake.
Correct: SnO₂ + 4HF → SnF₄ + 2H₂O
Then: Sn:1=1, O:2=2, H:4=4, F:4=4 → ✔
So probably typo — should be SnO₂, not SnO.
---
25) CaO + H₂ → Ca + H₂O — same as #8, already balanced ✔
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Now, summarizing corrections:
Many equations in the "answer key" have errors or typos. For accurate solving, here are the corrected balanced versions where needed:
- #4: Should be 4P + 5O₂ → 2P₂O₅
- #12: Should be 2Be + C → Be₂C (or similar)
- #15: Should be MgCl₂ + Pb(NO₃)₂ → Mg(NO₃)₂ + PbCl₂
- #17: Should be 2Fe(NO₃)₃ + 3MgF₂ → Fe₂F₆ + 3Mg(NO₃)₂
- #19: Should be AlCl₃ + (NH₄)₃PO₄ → AlPO₄ + 3NH₄Cl
- #21: Should be Na₂SO₄ + Sr(NO₃)₂ → 2NaNO₃ + SrSO₄
- #24: Should be SnO₂ + 4HF → SnF₄ + 2H₂O
Others are mostly correct as written.
Since the user asked to "solve the problem accurately", and the problem appears to be verifying or completing these equations, I will provide the fully corrected set.
But to match the format, I'll list each with its correct balanced form.
Final Answer:
Here is the accurate, corrected version of each equation:
1) Fe₂O₃ + 3H₂ → 2Fe + 3H₂O
2) CaO + H₂O → Ca(OH)₂
3) 2Na + 2H₂O → 2NaOH + H₂
4) 4P + 5O₂ → 2P₂O₅
5) CaC₂ + 2H₂O → C₂H₂ + Ca(OH)₂
6) 2Hg + O₂ → 2HgO
7) 2Br + Cl₂ → 2Cl + Br₂ *(note: unusual, but atom-balanced)*
8) CaO + H₂ → Ca + H₂O
9) 4Cr + 3SnCl₄ → 4CrCl₃ + 3Sn
10) AgNO₃ + NaCl → AgCl + NaNO₃
11) Mg + CuSO₄ → MgSO₄ + Cu
12) 2Be + C → Be₂C
13) ZnCO₃ → ZnO + CO₂
14) 2K + 2H₂O → 2KOH + H₂
15) MgCl₂ + Pb(NO₃)₂ → Mg(NO₃)₂ + PbCl₂
16) CaCN₂ + 3H₂O → CaCO₃ + 2NH₃
17) 2Fe(NO₃)₃ + 3MgF₂ → Fe₂F₆ + 3Mg(NO₃)₂
18) NaOH + HCl → H₂O + NaCl
19) AlCl₃ + (NH₄)₃PO₄ → AlPO₄ + 3NH₄Cl
20) FeS + H₂SO₄ → FeSO₄ + H₂S
21) Na₂SO₄ + Sr(NO₃)₂ → 2NaNO₃ + SrSO₄
22) Ba(OH)₂ + MgSO₄ → Mg(OH)₂ + BaSO₄
23) 2Na + 2H₂O → 2NaOH + H₂
24) SnO₂ + 4HF → SnF₄ + 2H₂O
25) CaO + H₂ → Ca + H₂O
All equations are now correctly balanced with proper chemical formulas.
Parent Tip: Review the logic above to help your child master the concept of practice balancing chemical equations worksheet with answers.
![49 Balancing Chemical Equations Worksheets [with Answers]](/images2/practice-balancing-chemical-equations-worksheet-with-answers/practice-balancing-chemical-equations-worksheet-with-answers-7.jpg)
![49 Balancing Chemical Equations Worksheets [with Answers]](/images2/practice-balancing-chemical-equations-worksheet-with-answers/practice-balancing-chemical-equations-worksheet-with-answers-33.jpg)
