Balancing Chemical Equations

Question 1

Which coefficients balance __ C3H8 + __ O2 → __ CO2 + __ H2O?

Accepted Answer

1, 5, 3, 4

Answer

1, 3, 3, 4

Answer

2, 5, 3, 4

Answer

1, 5, 4, 3

Question 2

For __ Fe + __ O2 → __ Fe2O3, which coefficient set is balanced?

Accepted Answer

4, 3, 2

Answer

2, 3, 1

Answer

2, 1, 1

Answer

1, 1, 1

Question 3

Choose the coefficients that balance __ N2 + __ H2 → __ NH3.

Accepted Answer

1, 3, 2

Answer

1, 1, 2

Answer

2, 3, 2

Answer

1, 2, 3

Question 4

Which coefficients balance __ H2O2 → __ H2O + __ O2?

Accepted Answer

2, 2, 1

Answer

1, 1, 1

Answer

2, 1, 1

Answer

1, 2, 1

Question 5

Balance __ Al + __ HCl → __ AlCl3 + __ H2 by choosing the correct coefficients.

Accepted Answer

2, 6, 2, 3

Answer

1, 3, 1, 1

Answer

2, 3, 2, 3

Answer

2, 6, 1, 3

Question 6

Which coefficient set balances __ C2H6 + __ O2 → __ CO2 + __ H2O?

Accepted Answer

2, 7, 4, 6

Answer

1, 7, 4, 6

Answer

2, 5, 4, 6

Answer

2, 7, 6, 4

Question 7

What coefficients balance __ KClO3 → __ KCl + __ O2?

Accepted Answer

2, 2, 3

Answer

1, 1, 1

Answer

2, 1, 3

Answer

1, 2, 3

Question 8

Select the coefficients for __ Mg + __ N2 → __ Mg3N2.

Accepted Answer

3, 1, 1

Answer

1, 1, 1

Answer

2, 1, 1

Answer

3, 2, 1

Question 9

Which coefficients make __ Na + __ Cl2 → __ NaCl balanced?

Accepted Answer

2, 1, 2

Answer

1, 1, 1

Answer

1, 2, 2

Answer

2, 2, 1

Question 10

For methane combustion, which coefficients balance __ CH4 + __ O2 → __ CO2 + __ H2O?

Accepted Answer

1, 2, 1, 2

Answer

1, 1, 1, 2

Answer

1, 2, 2, 1

Answer

2, 2, 1, 2

Question 11

Which coefficients balance __ P4 + __ O2 → __ P2O5?

Accepted Answer

1, 5, 2

Answer

1, 2, 1

Answer

2, 5, 2

Answer

1, 4, 2

Question 12

Find the coefficients for __ Zn + __ HCl → __ ZnCl2 + __ H2.

Accepted Answer

1, 2, 1, 1

Answer

1, 1, 1, 1

Answer

2, 1, 1, 1

Answer

1, 2, 2, 1

Question 13

Which coefficients balance __ C4H10 + __ O2 → __ CO2 + __ H2O?

Accepted Answer

2, 13, 8, 10

Answer

1, 13, 8, 10

Answer

2, 10, 8, 10

Answer

2, 13, 10, 8

Question 14

Which coefficient set balances __ Li + __ O2 → __ Li2O?

Accepted Answer

4, 1, 2

Answer

2, 1, 1

Answer

1, 1, 2

Answer

4, 2, 2

Question 15

Choose the coefficients for __ C2H4 + __ O2 → __ CO2 + __ H2O.

Accepted Answer

1, 3, 2, 2

Answer

1, 2, 2, 2

Answer

2, 3, 2, 2

Answer

1, 3, 1, 2

Question 16

What coefficients balance __ H2 + __ Cl2 → __ HCl?

Accepted Answer

1, 1, 2

Answer

1, 1, 1

Answer

2, 1, 2

Answer

1, 2, 2

Question 17

Which coefficients balance __ C3H6 + __ O2 → __ CO2 + __ H2O?

Accepted Answer

2, 9, 6, 6

Answer

1, 9, 6, 6

Answer

2, 6, 6, 6

Answer

2, 9, 3, 6

Question 18

Select the coefficients that balance __ SO2 + __ O2 → __ SO3.

Accepted Answer

2, 1, 2

Answer

1, 1, 1

Answer

1, 2, 2

Answer

2, 2, 1

Question 19

For __ CO + __ O2 → __ CO2, which coefficients are correct?

Accepted Answer

2, 1, 2

Answer

1, 1, 1

Answer

1, 2, 2

Answer

2, 2, 1

Question 20

Which coefficients balance __ C2H2 + __ O2 → __ CO2 + __ H2O?

Accepted Answer

2, 5, 4, 2

Answer

1, 5, 4, 2

Answer

2, 3, 4, 2

Answer

2, 5, 2, 4

Question 21

Which statement correctly judges 2H2 + O2 → 2H2O?

Accepted Answer

Yes; each side has 4 H atoms and 2 O atoms.

Answer

No; the product side has more oxygen atoms.

Answer

Yes; each side has 2 H atoms and 1 O atom.

Answer

No; coefficients are not allowed in balanced equations.

Question 22

Is Fe + O2 → Fe2O3 balanced?

Accepted Answer

No; the left side has 1 Fe and 2 O, while the right side has 2 Fe and 3 O.

Answer

Yes; both sides contain iron and oxygen.

Answer

No; products cannot contain oxygen.

Answer

Yes; Fe2O3 has five total atoms.

Question 23

Which judgment is correct for 2Na + Cl2 → 2NaCl?

Accepted Answer

Yes; there are 2 Na atoms and 2 Cl atoms on each side.

Answer

No; chlorine has a subscript on only one side.

Answer

Yes; there is one Na atom and one Cl atom on each side.

Answer

No; sodium must be written as Na2 to balance it.

Question 24

Check C + O2 → CO. Which statement is accurate?

Accepted Answer

No; oxygen changes from 2 atoms on the left to 1 atom on the right.

Answer

Yes; carbon is balanced, so the whole equation is balanced.

Answer

No; carbon disappears on the product side.

Answer

Yes; CO and O2 both contain oxygen.

Question 25

Which statement correctly evaluates 2KClO3 → 2KCl + 3O2?

Accepted Answer

Yes; both sides have 2 K atoms, 2 Cl atoms, and 6 O atoms.

Answer

No; oxygen gas cannot have a coefficient.

Answer

Yes; both sides have 2 K atoms, 2 Cl atoms, and 3 O atoms.

Answer

No; the product side has no chlorine atoms.

Question 26

Is CaCO3 → CaO + CO2 balanced?

Accepted Answer

Yes; each side has 1 Ca atom, 1 C atom, and 3 O atoms.

Answer

No; the carbonate subscript must stay together on the product side.

Answer

Yes; each side has 1 Ca atom and 1 O atom only.

Answer

No; a decomposition reaction cannot be balanced.

Question 27

Which statement is correct for Mg + 2HCl → MgCl2 + H2?

Accepted Answer

Yes; Mg, H, and Cl atom counts are equal on both sides.

Answer

No; the coefficient 2 changes chlorine into magnesium.

Answer

Yes; it is balanced because there are two products.

Answer

No; hydrogen is lost because it becomes a gas.

Question 28

Is Al + 3Br2 → AlBr3 balanced?

Accepted Answer

No; the left side has 6 Br atoms, but the right side has 3 Br atoms.

Answer

Yes; one aluminum atom appears on each side.

Answer

No; bromine cannot form a compound with aluminum.

Answer

Yes; the coefficient 3 makes three AlBr3 units.

Question 29

Which equation balances aluminum reacting with oxygen by changing coefficients only?

Accepted Answer

4Al + 3O2 → 2Al2O3

Answer

Al2 + O3 → Al2O3

Answer

2Al + O2 → Al2O3

Answer

Al + O2 → AlO2

Question 30

Sodium reacts with water to form sodium hydroxide and hydrogen. Which equation is balanced by coefficients only?

Accepted Answer

2Na + 2H2O → 2NaOH + H2

Answer

Na + H2O → NaOH + H2

Answer

Na + H2O2 → NaOH + H2

Answer

2Na + H2O → Na2O + H2

Question 31

Which coefficient-only change correctly balances mercury(II) oxide decomposing?

Accepted Answer

2HgO → 2Hg + O2

Answer

HgO → Hg + O2

Answer

HgO2 → Hg + O2

Answer

2HgO → Hg2 + O2

Question 32

Magnesium reacts with hydrochloric acid. Which equation fixes the balancing by using coefficients, not subscripts?

Accepted Answer

Mg + 2HCl → MgCl2 + H2

Answer

Mg + HCl → MgCl2 + H2

Answer

Mg + H2Cl2 → MgCl2 + H2

Answer

Mg + 2HCl → MgCl + H2

Question 33

Which equation shows glucose combustion balanced by coefficients only?

Accepted Answer

C6H12O6 + 6O2 → 6CO2 + 6H2O

Answer

C6H12O6 + O2 → CO2 + H2O

Answer

C6H12O6 + 3O2 → 6CO2 + 6H2O

Answer

C6H12O6 + 6O2 → 6CO + 6H2O

Question 34

Iron reacts with hydrochloric acid to form iron(II) chloride and hydrogen. Which equation is balanced correctly?

Accepted Answer

Fe + 2HCl → FeCl2 + H2

Answer

Fe + HCl → FeCl2 + H2

Answer

Fe + HCl2 → FeCl2 + H

Answer

Fe2 + 2HCl → 2FeCl + H2

Question 35

Keeping SO4 together, which coefficients balance __ BaCl2 + __ Na2SO4 → __ BaSO4 + __ NaCl?

Accepted Answer

1, 1, 1, 2

Answer

1, 2, 1, 1

Answer

2, 1, 1, 2

Answer

1, 1, 2, 2

Question 36

Treating SO4 and OH as unchanged groups, balance __ Al2(SO4)3 + __ Ca(OH)2 → __ Al(OH)3 + __ CaSO4.

Accepted Answer

1, 3, 2, 3

Answer

1, 2, 2, 3

Answer

2, 3, 2, 3

Answer

1, 3, 3, 2

Question 37

Which coefficients balance __ Pb(NO3)2 + __ KI → __ PbI2 + __ KNO3 while keeping nitrate together?

Accepted Answer

1, 2, 1, 2

Answer

1, 1, 1, 1

Answer

2, 1, 1, 2

Answer

1, 2, 2, 1

Question 38

Balance __ (NH4)2CO3 + __ CaCl2 → __ CaCO3 + __ NH4Cl by treating NH4 as a group.

Accepted Answer

1, 1, 1, 2

Answer

1, 2, 1, 1

Answer

2, 1, 1, 2

Answer

1, 1, 2, 1

Question 39

What coefficients balance __ Na3PO4 + __ MgCl2 → __ Mg3(PO4)2 + __ NaCl?

Accepted Answer

2, 3, 1, 6

Answer

1, 3, 1, 3

Answer

2, 1, 1, 6

Answer

3, 2, 1, 6

Question 40

Keeping phosphate together, choose coefficients for __ Ca(OH)2 + __ H3PO4 → __ Ca3(PO4)2 + __ H2O.

Accepted Answer

3, 2, 1, 6

Answer

1, 2, 1, 3

Answer

3, 1, 1, 6

Answer

2, 3, 1, 6

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Balancing Chemical Equations

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Balancing Chemical Equations

Ways to Play

Device Games: Students play on their phones

Blast Go

Zombie Escape

Avalanche

Maze Blast

Cave Climb

Blast Out

Mystery Auction

Tour Guide

Food Truck Rush

Tug of War

Alien Blast

Glacier Rush

Board Games: Teacher-led, projected to the class

Like what you see?

More like this

Bug Blast

BlastRace

BlastQuiz

BlastBoard

Seek & Destroy

Mystery Blast

Checkers

Texas Hold 'Em

Da Bomb

Castle Siege

Hot Potato

Market Mayhem

King of the Hill

Bank Heist

Top Corner