Question

Complete and balance the following half-reaction in basic solution. Be sure to include the proper phases for all species within the reaction for Zn(s)→Zn(OH) 42− (aq).

A) Zn(s)+4OH − (aq)→Zn(OH) 42−(aq)+4e −
B) Zn(s)+2OH −(aq)→Zn(OH) 2(aq)+2e −
C) Zn(s)+2H2 O(l)→Zn(OH)2 (aq)+2H2(g)
D)Zn(s)+4H2 O(l)→Zn(OH)42− (aq)+4H2(g)

Answer 1

The correct balanced half-reaction of zinc to Zn(OH)4^2- in basic solution is Zn(s) + 4OH− (aq) → Zn(OH)4^2− (aq) + 2e−, which indicates that option A is the correct answer.

Step-by-step explanation:

To complete and balance the half-reaction of zinc metal to Zn(OH)42− (aq) in basic solution, we must ensure that the number of atoms and the charge is balanced on both sides of the reaction. Given the options, the correct balanced equation is:

Zn(s) + 4OH− (aq) → Zn(OH)42− (aq) + 2e−

This choice, when compared to the other options, correctly balances the zinc atoms, hydroxide ions, and the charge, following the rules for balancing reactions in basic media. Here's how it's confirmed:

• The zinc atom on the left side equals the zinc in the complex ion Zn(OH)42− on the right.
• Four OH− are added to each zinc atom to become Zn(OH)42−.
• Charge is balanced by adding 2 electrons to the right side to offset the 2+ charge of the Zn2+ ion in Zn(OH)42−.
• Therefore, the correct answer is option A.