2. What is the reduction half-reaction for the following unbalanced redox equation?

Cr2O72– + NH4+ Cr2O3 + N2

A.) Cr2O3 -> Cr2O7^2–
*B.) Cr2O72– -> Cr2O3
C.) NH4+ -> N2
D.) N2 -> NH4+

3. Which oxidation-reduction reactions are best balanced by the half-reaction method?

A.) covalent reactions
B.) acid-base reactions
*C.) ionic reactions
D.) intermolecular reactions

Thank you.

2. b

3. is correct

2. The reduction half-reaction for the given unbalanced redox equation is option B.) Cr2O72– -> Cr2O3.

3. The oxidation-reduction reactions that are best balanced by the half-reaction method are ionic reactions. So, the correct answer is option C.) ionic reactions.

You're welcome! If you have any more questions, feel free to ask!

2. The reduction half-reaction for the given unbalanced redox equation "Cr2O72– + NH4+ Cr2O3 + N2" is option B.) Cr2O72– -> Cr2O3.

3. The oxidation-reduction reactions that are best balanced by the half-reaction method are ionic reactions, so the correct answer is option C.) ionic reactions.

To determine the reduction half-reaction for the given unbalanced redox equation, we need to first identify the species that is being reduced. In this case, the species Cr2O72– is being reduced to Cr2O3.

To balance the charges in the reduction half-reaction, we need to determine the change in oxidation state of the element being reduced. In Cr2O72–, each Cr atom has an oxidation state of +6, while in Cr2O3, each Cr atom has an oxidation state of +3. Therefore, the oxidation state of Cr is decreasing by 3.

To balance the reduction half-reaction, we place the Cr2O72– on the reactant side and the Cr2O3 on the product side. Since the oxidation state of Cr is decreasing, we can represent the reduction half-reaction as:

Cr2O72– + 14H+ + 6e– -> Cr2O3 + 7H2O

Therefore, the correct answer for the reduction half-reaction is B.) Cr2O72– -> Cr2O3.

Moving on to the second question, the half-reaction method is best suited for balancing ionic reactions. Ionic reactions involve the transfer of electrons between species, which is exactly what the half-reaction method focuses on.

Therefore, the correct answer for the second question is C.) ionic reactions.

You're welcome! If you have any more questions, feel free to ask.