Balancing Redox Equations

Which equation is balanced?

• PbO₂ + 2H₂--> H₂SO₄

• SO₂ + H₂0 --> H₂SO₄

• 2Na + 2H₂O --> 2NaOH + H₂

• 2Na + 2H₂O --> 2NaOH + H

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-7

Balance this equation:
P₄+O₂  -->  P₂O₃

• 3 P₄+ O₂ --> 2 P₂O₃

•  P₄+ O₂ --> 2 P₂O₃

•  P₄+ 3 O₂ --> 2 P₂O₃

•  P₄+ 2 O₂ --> 3 P₂O₃

Tags

NGSS.HS-PS1-7

How many atoms of aluminum are on each side of the following equation: 4Al + 3O₂ --> 2Al₂ O₃

• 2

• 6

• 1

• 4

Tags

NGSS.HS-PS1-7

Which number should go in the blank?
_ H₂ + O₂ -> 2 H₂O

• 1

• 2

• 3

• 0

Tags

NGSS.HS-PS1-7

Balance this equation
_Zn+_HCl-->_ZnCl₂ +_H₂

• 1,1,2,1

• 1,1,1,2

• 1,2,1,1

• 2,1,1,1

Tags

NGSS.HS-PS1-7

When balancing equations a ____ can be placed to the left of a formula of a substance to make the equations balanced

• charge

• subscript

• random number

• coefficient

Which of the following redox equations is balanced?

• @@ ext{MnO}_4^- + ext{Fe}^{2+} ightarrow ext{Mn}^{2+} + ext{Fe}^{3+}@@

• @@ ext{MnO}_4^- + 5 ext{Fe}^{2+} + 8 ext{H}^+ ightarrow ext{Mn}^{2+} + 5 ext{Fe}^{3+} + 4 ext{H}_2 ext{O}@@

• @@ ext{MnO}_4^- + 4 ext{Fe}^{2+} + 8 ext{H}^+ ightarrow ext{Mn}^{2+} + 4 ext{Fe}^{3+} + 4 ext{H}_2 ext{O}@@

• @@ ext{MnO}_4^- + 6 ext{Fe}^{2+} + 8 ext{H}^+ ightarrow ext{Mn}^{2+} + 6 ext{Fe}^{3+} + 4 ext{H}_2 ext{O}@@

Tags

NGSS.HS-PS1-7

Balance the following redox equation: @@ ext{Cr}_2 ext{O}_7^{2-} + ext{Fe}^{2+} + ext{H}^+ ightarrow ext{Cr}^{3+} + ext{Fe}^{3+} + ext{H}_2 ext{O}@@

• @@ ext{Cr}_2 ext{O}_7^{2-} + 6 ext{Fe}^{2+} + 14 ext{H}^+ ightarrow 2 ext{Cr}^{3+} + 6 ext{Fe}^{3+} + 7 ext{H}_2 ext{O}@@

• @@ ext{Cr}_2 ext{O}_7^{2-} + 5 ext{Fe}^{2+} + 14 ext{H}^+ ightarrow 2 ext{Cr}^{3+} + 5 ext{Fe}^{3+} + 7 ext{H}_2 ext{O}@@

• @@ ext{Cr}_2 ext{O}_7^{2-} + 6 ext{Fe}^{2+} + 12 ext{H}^+ ightarrow 2 ext{Cr}^{3+} + 6 ext{Fe}^{3+} + 6 ext{H}_2 ext{O}@@

• @@ ext{Cr}_2 ext{O}_7^{2-} + 6 ext{Fe}^{2+} + 14 ext{H}^+ ightarrow 2 ext{Cr}^{3+} + 6 ext{Fe}^{3+} + 6 ext{H}_2 ext{O}@@

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-7

In the redox reaction @@ ext{Zn} + ext{Cu}^{2+} ightarrow ext{Zn}^{2+} + ext{Cu}@@, which element is oxidized?

• Zinc (Zn)

• Copper (Cu)

• Zinc ion (Zn^{2+})

• Copper ion (Cu^{2+})

Which of the following is a correct half-reaction for the reduction of permanganate ion in acidic solution?

• @@ ext{MnO}_4^- + 8 ext{H}^+ + 5 ext{e}^- ightarrow ext{Mn}^{2+} + 4 ext{H}_2 ext{O}@@

• @@ ext{MnO}_4^- + 4 ext{H}^+ + 3 ext{e}^- ightarrow ext{MnO}_2 + 2 ext{H}_2 ext{O}@@

• @@ ext{MnO}_4^- + 2 ext{H}_2 ext{O} + 3 ext{e}^- ightarrow ext{MnO}_2 + 4 ext{OH}^-@@

• @@ ext{MnO}_4^- + 2 ext{H}_2 ext{O} + 5 ext{e}^- ightarrow ext{Mn}^{2+} + 4 ext{OH}^-@@

Tags

NGSS.HS-PS1-2