U11 Post-Assessment Remediation (PAR)

What is the oxidation number of manganese in KMnO₄?

• +7

• +2

• +3

• +4

Which element reacts spontaneously with 1.0 M HCl(aq) at room temperature?

• copper

• gold

• silver

• zinc

Tags

NGSS.HS-PS1-1

During the operation of a voltaic cell, the cell produces

• electrical energy spontaneously

• chemical energy spontaneously

• electrical energy nonspontaneously

• chemical energy nonspontaneously

Which balanced equation represents an oxidation-reduction reaction?

• Ba(NO₃)₂ + Na₂SO₄ → BaSO₄ + 2NaNO₃

• H₃PO₄ + 3KOH → K₃PO₄ + 3H₂O

• Fe(s) + S(s) → FeS(s)

The diagram attached represents an operating electrochemical cell and the balanced ionic equation for the reaction occurring in the cell. Which statement identifies the part of the cell that conducts electrons and describes the direction of electron flow as the cell operates?

• Electrons flow through the salt bridge from the Ni(s) to the Zn(s).

• Electrons flow through the salt bridge from the Zn(s) to the Ni(s).

• Electrons flow through the wire from the Ni(s) to the Zn(s).

• Electrons flow through the wire from the Zn(s) to the Ni(s).

Tags

NGSS.HS-PS2-5

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-PS1-1

NGSS.HS-PS1-2

Which statement describes electrolysis?

• Chemical energy is used to produce an electrical change.

• Chemical energy is used to produce a thermal change.

• Electrical energy is used to produce a chemical change.

• Thermal energy is used to produce a chemical change.

Tags

NGSS.HS-PS3-2

Given the balanced ionic equation representing a reaction: 2Al³⁺(aq) + 3Mg(s) → 3Mg²⁺(aq) + 2Al(s). In this reaction, electrons are transferred from:

• Al to Mg²⁺

• Al³⁺ to Mg

• Mg to Al³⁺

• Mg²⁺ to Al

Tags

NGSS.HS-PS1-2

Given the balanced equation representing the reaction occurring in a voltaic cell: Zn(s) + Pb²⁺(aq) → Zn²⁺(aq) + Pb(s). In the completed external circuit, the electrons flow from:

• Pb(s) to Zn(s)

• Pb²⁺(aq) to Zn²⁺(aq)

• Zn(s) to Pb(s)

• Zn²⁺(aq) to Pb²⁺(aq)

Tags

NGSS.HS-PS3-5

Which changes occur when Pt²⁺ is reduced?

• The Pt²⁺ gains electrons and its oxidation number increases.

• The Pt²⁺ gains electrons and its oxidation number decreases.

• The Pt²⁺ loses electrons and its oxidation number increases.

• The Pt²⁺ loses electrons and its oxidation number decreases.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2