Unit 13 Exam Electrochemistry

What is the oxidation number of iodine in KIO4?

• +1

• –1

• +7

• –7

Given the balanced equation representing a reaction: 2KClO3(s) → 2KCl(s) + 3O2(g) The oxidation state of chlorine in this reaction changes from

• –1 to +1

• –1 to +5

• +1 to –1

• +5 to –1

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

In an oxidation-reduction reaction, the number of electrons lost is

• equal to the number of electrons gained

• equal to the number of protons gained

• less than the number of electrons gained

• less than the number of protons gained

Which half-reaction correctly represents reduction?

• Mn4+ → Mn3+ + e–

• Mn4+ → Mn7+ + 3e–

• Mn4+ + e– → Mn3+

• Mn4+ + 3e– → Mn7+

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Given the balanced ionic equation representing a reaction: 2Al(s) + 3Cu2+(aq) → 2Al3+(aq) + 3Cu(s) Which half-reaction represents the reduction that occurs?

• Al → Al3+ + 3e

• Al3+ + 3e → Al

• Cu → Cu2+ + 2e

• Cu2+ + 2e → Cu

Tags

NGSS.HS-PS1-2

Given the balanced equation representing a reaction: Fe2O3 + 2Al → Al2O3 + 2Fe During this reaction, the oxidation number of Fe changes from

• +2 to 0 as electrons are transferred

• +2 to 0 as protons are transferred

• +3 to 0 as electrons are transferred

• +3 to 0 as protons are transferred

Tags

NGSS.HS-PS1-2

Which balanced equation represents a redox reaction?

• PCl5 → PCl3 + Cl2

• KOH + HCl → KCl + H2O

• LiBr → Li+ + Br–

• Ca2+ + SO4 2– → CaSO4

Which metal will spontaneously react with Zn2+(aq), but will not spontaneously react with Mg2+(aq)?

• Mn(s)

• Cu(s)

• Ni(s)

• Ba(s)

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which metal is more active than H2?

• Ag

• Au

• Cu

• Pb

Given the balanced equation representing a reaction: 2Fe + 3Cu2+ → 2Fe3+ + 3Cu When the iron atoms lose six moles of electrons, how many moles of electrons are gained by the copper ions?

• 12 moles

• 2 moles

• 3 moles

• 6 moles

Tags

NGSS.HS-PS1-2