Balancing Equations

Which of the following is the correctly balanced equation for the combustion of methane?

• @@ ext{CH}_4 + ext{O}_2 ightarrow ext{CO}_2 + ext{H}_2 ext{O}@@

• @@ ext{CH}_4 + 2 ext{O}_2 ightarrow ext{CO}_2 + 2 ext{H}_2 ext{O}@@

• @@ ext{CH}_4 + ext{O}_2 ightarrow ext{CO}_2 + 2 ext{H}_2 ext{O}@@

• @@ ext{CH}_4 + 2 ext{O}_2 ightarrow ext{CO}_2 + ext{H}_2 ext{O}@@

What is the coefficient of oxygen when balancing the equation for the reaction of hydrogen and oxygen to form water?

• 1

• 2

• 3

• 4

Tags

NGSS.MS-PS1-5

In the balanced equation @@ ext{N}_2 + 3 ext{H}_2 ightarrow 2 ext{NH}_3@@, what is the ratio of hydrogen molecules to ammonia molecules?

• 1:1

• 2:3

• 3:2

• 3:1

Tags

NGSS.HS-PS1-7

Which of the following represents a balanced chemical equation for the decomposition of water?

• @@ ext{H}_2 ext{O} ightarrow ext{H}_2 + ext{O}_2@@

• @@2 ext{H}_2 ext{O} ightarrow 2 ext{H}_2 + ext{O}_2@@

• @@2 ext{H}_2 ext{O} ightarrow ext{H}_2 + ext{O}_2@@

• @@ ext{H}_2 ext{O} ightarrow 2 ext{H}_2 + ext{O}_2@@

Tags

NGSS.MS-PS1-5

When balancing the equation @@ ext{Fe} + ext{O}_2 ightarrow ext{Fe}_2 ext{O}_3@@, what is the coefficient of iron (Fe)?

• 1

• 2

• 3

• 4

Tags

NGSS.MS-PS1-5

• 3

• 4

• 5

• 6

Tags

NGSS.HS-PS1-7

Which of the following is a balanced equation for the reaction of sodium with water?

• @@ ext{Na} + ext{H}_2 ext{O} ightarrow ext{NaOH} + ext{H}_2@@

• @@2 ext{Na} + 2 ext{H}_2 ext{O} ightarrow 2 ext{NaOH} + ext{H}_2@@

• @@2 ext{Na} + ext{H}_2 ext{O} ightarrow ext{NaOH} + ext{H}_2@@

• @@ ext{Na} + 2 ext{H}_2 ext{O} ightarrow 2 ext{NaOH} + ext{H}_2@@

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

What is the balanced equation for the reaction of aluminum with hydrochloric acid?

• @@ ext{Al} + ext{HCl} ightarrow ext{AlCl}_3 + ext{H}_2@@

• @@2 ext{Al} + 6 ext{HCl} ightarrow 2 ext{AlCl}_3 + 3 ext{H}_2@@

• @@ ext{Al} + 3 ext{HCl} ightarrow ext{AlCl}_3 + ext{H}_2@@

• @@2 ext{Al} + 3 ext{HCl} ightarrow 2 ext{AlCl}_3 + 3 ext{H}_2@@

• 1

• 3

• 6

• 12

Which of the following is the balanced equation for the reaction of calcium carbonate decomposing into calcium oxide and carbon dioxide?

• @@ ext{CaCO}_3 ightarrow ext{CaO} + ext{CO}_2@@

• @@2 ext{CaCO}_3 ightarrow 2 ext{CaO} + ext{CO}_2@@

• @@ ext{CaCO}_3 ightarrow ext{CaO} + 2 ext{CO}_2@@

• @@2 ext{CaCO}_3 ightarrow ext{CaO} + 2 ext{CO}_2@@

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2