WorksheetsU11 Post-Assessment Remediation (PAR)
Total questions: 15
Worksheet time: 8mins
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
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).
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
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.
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
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)
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.
Base your answer to the question on the diagram of the voltaic cell. Identify the half reaction that occurs in half-cell 2
Pb(s) → Pb2+(aq) + 2e-
Ag(s) → Ag+(aq) + 2e-
Pb2+(aq) + 2e- → Pb(s)
2Ag+(aq) + 2e- → Ag(s)
Which equation shows conservation of both mass and charge?
Cl2 + Br- → Cl- + Br2
Cu + 2Ag+ → Cu2+ + Ag
Zn + Cr3+ → Zn2+ + Cr
Ni + Pb2+ → Ni2+ + Pb
Given the balanced equation representing a reaction occurring in an electrolytic cell:
2NaCl(l)==> 2Na(l) + Cl2(g)
Where is Na(l) produced in the cell?
at the anode, where oxidation occurs
at the anode, where reduction occurs
at the cathode, where oxidation occurs
at the cathode, where reduction occurs
What will happen to the mass of the zinc metal?
increases as Zn oxidizes to Zn2+
decrease as Zn oxidizes to Zn2+
increases as Zn2+ reduces to Zn
decreases as Zn2+ reduces to Zn
According to Table J, which of the following ions will cause Mg+2(aq) to be reduced?
Na
Al
Fe
Au
