Use the chemical equation to complete the activity.
Ha(g) + l2 (g) - 2HI(g)
A student makes the following statements:
• Hydrogen always has the same oxidation number, so it has an oxidation number of +1 in both the reactant H and product
HI.
• lodine is in Group VIA, so it has an oxidation number of -1 in both the reactant I and product HI.
• Neither hydrogen nor iodine changes oxidation states, so the reaction is not a redox reaction.
In three to five sentences, describe the mistake that the student made, and determine whether or not the reaction is a redox
reaction. Explain your answer.
(4 points)
1 answer
The student's mistake is assuming that the oxidation numbers for hydrogen and iodine remain constant throughout the reaction. In reality, the oxidation number of hydrogen changes from 0 in the reactant Ha to +1 in the product HI. The oxidation number of iodine also changes from 0 in the reactant I2 to -1 in the product HI. Therefore, the reaction is indeed a redox reaction because there is a change in oxidation states for both hydrogen and iodine.
5 answers