Textbook Question
At 900 °C, titanium tetrachloride vapor reacts with molten magnesium metal to form solid titanium metal and molten magnesium chloride (c) Which substance is the reductant, and which is the oxidant?
6. Chemical Quantities & Aqueous Reactions
Redox Reactions
Multiple Choice
Considering the redox reaction Cr + Ni²⁺ → Cr³⁺ + Ni, how many electrons are transferred in the balanced reaction?
A
1 electron
B
3 electrons
C
2 electrons
D
4 electrons
Verified step by step guidance1
Identify the oxidation states of the elements in the reactants and products. Chromium (Cr) starts with an oxidation state of 0 and changes to +3 in Cr³⁺. Nickel (Ni) starts with an oxidation state of +2 in Ni²⁺ and changes to 0 in Ni.
Determine the change in oxidation state for each element. Chromium goes from 0 to +3, indicating it loses 3 electrons. Nickel goes from +2 to 0, indicating it gains 2 electrons.
Write the half-reactions for oxidation and reduction. The oxidation half-reaction is Cr → Cr³⁺ + 3e⁻, and the reduction half-reaction is Ni²⁺ + 2e⁻ → Ni.
Balance the number of electrons transferred in each half-reaction. To balance the electrons, multiply the oxidation half-reaction by 2 and the reduction half-reaction by 3, so both involve 6 electrons.
Combine the balanced half-reactions to form the overall balanced redox reaction, ensuring that the number of electrons lost equals the number of electrons gained.
Related Videos
Related Practice
