Pre-test in REDOX reaction

The reaction 2 NaCl --> 2 Na + Cl₂ is an example of

• A reduction reaction only

• An oxidation reaction only

• Both an oxidation and reduction reaction

• Neither an oxidation nor a reduction reaction

Oxidation-reduction reactions occur because of the competition between particles for

• protons

• neutrons

• positrons

• electrons

Which one of the following reactions is an oxidation reduction reaction?

• NaCl + AgNO₃ → AgCl + NaNO₃

• CaSO₃ + 2HCl → CaCl₂ + H₂O + SO₂

• 3Ca(OH)₂ + 2H₃PO₄ → Ca₃(PO₄)₂ + 3H₂O

• 3CuO + 2NH₃ → 3Cu + 3H₂O + N₂

As an element is oxidized, its oxidation number

• Increases as electrons are gained

• Decreases as electrons are gained

• Decreases as electrons are lost

• Increases as electrons are lost

Mg + PbCl₂ --> MgCl₂ + Pb. Which statement correctly describes the oxidation and reduction that occur?

• Mg is oxidized and Cl^- is reduced

• Mg is oxidized  and Pb⁺² is reduced

• Mg is reduced and Cl^- is oxidized

• Mg is reduced and Pb⁺² is oxidized