Balancing Redox Equations

Which of the following reactions is balanced by both mass and charge?

• Fe⁺² + Al →Fe + Al⁺³
• Cu + Fe⁺² → Cu⁺¹ + Fe⁺³
• F₂ + Br^- --> F^- + Br₂
• Fe⁺² + 2 Cu --> 2 Cu⁺ + Fe

Tags

NGSS.HS-PS1-7

Which of the following is the balanced half -reaction for the oxidation of Cu to Cu^+2?

• Cu   --> Cu⁺²
• Cu + 2 e-   --> Cu⁺²
• Cu  --> Cu⁺²  + 2 e-
• Cu - 2e-  --> Cu⁺²

Tags

NGSS.HS-PS1-7

What are α and β and γ?

NO₃^- + α H⁺ + β e^- → NO + γ H₂O

• α = 2 β = 3 γ = 4

• α = 2 β = 2 γ = 2

• α = 4 β = 4 γ = 3

• α = 4 β = 3 γ = 2

Tags

NGSS.HS-PS1-7

Which of these equations represents a redox reaction?

• Ca(HCO₃)_{2 -->} CaCO₃ + H₂O + CO₂

• HC₂H₃O₂ + NaOH --> NaC₂H₃O₂ + H₂O

• Zn + 2FeCl₃ --> ZnCl₂ + 2FeCl₂

• NaCl + AgNO_{3 -->} AgCl + NaNO₃

Tags

NGSS.HS-PS1-7

Which element is being oxidized in the following chemical reaction?

2KMnO₄ + 5KNO₂ + 3H₂SO₄ --> 2MnSO₄ + 3H₂O + 5KNO₃ + K₂SO₄

• S

• Mn

• O

• N

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which element is reduced in the following reaction?

2K₂Cr₂O₇ + 2H₂O + 3S --> 3SO₂ + 4KOH + 2Cr₂O₃

• K

• Cr

• O

• S

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

• Zn    +    HgO

• ZnO     +     Hg

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

• Zn    +    HgO

• ZnO     +     Hg

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

When an element undergoes combustion and loses electrons, the element is

• oxidized

• reduced

• neutralized

• dissolved

Tags

NGSS.HS-PS1-2

In the reaction
2Ca(s) + O₂(g) → 2CaO(s), calcium is...

• Reduced
• Synthesized
• Oxidized
• None of the above