Question

Use the chemical equation to complete the activity.

H2(g) + I2(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 H2 and product HI.
Iodine is in Group VIIA, so it has an oxidation number of –1 in both the reactant I2 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.

Answer 1

OXIDATION UNIT TEST

1. Which statement best explains why magnesium and chlorine combine in a 1:2 ratio?

A. Magnesium has two valence electrons, and chlorine can accept one electron in its outer shell

2. Hydrogen and nitrogen combine to form ammonia. When nitrogen and hydrogen bond, nitrogen pulls the electrons from hydrogen toward itself. Which statement about the reactants is correct?

C. Hydrogen is oxidized, and nitrogen is reduced.

3. C3H8 + 5O2 → 3CO2 + 4H2O + energy

Which type of reaction is shown?

C. combustion

4. Which phrase best defines a redox reaction?

D. a reaction in which electrons are transferred between different atoms

5. Which statement describes the process of oxidation?

D. Oxidation results in a loss of electrons, so the oxidation number increases.

6. Which chemical equation represents a redox reaction?

D. Fe2O3(s) + 2Al(s) → Al2O3(s) + 2Fe(l)

7. Which statement correctly describes the oxidation number of the manganese atom (Mn) in MnI2 and MnO2?

A. Manganese has an oxidation number of +2 in MnI2 and +4 in MnO2.

8. Br2(l) + 2NaI(aq) → I2(s) + 2NaBr(aq)

Which elements are oxidized and reduced in the reaction?

D. Iodine (I) is oxidized, and bromine (Br) is reduced.

9. Which action occurs at an electrode of a galvanic cell?

D. electron transfer

10. Which statement best compares a battery and a galvanic cell?

A. A battery’s source of power is a galvanic cell in which a redox reaction produces electrical energy.

11. Zn + 2H+ → Zn2+ + H2

2Al + 3Cu2+ → 2Al3+ + 3Cu

Which elements are oxidized?

A. zinc (Zn) and aluminum (Al)

12. 2Cr(s) + 3Cu2+(aq) → 2Cr3+(aq) + 3Cu(s)

Which half reaction occurs at the cathode?

B. 3Cu2+(aq) + 6e– → 3Cu(s)

13. Written

14. Written

15. Written

I hope this helps!

Answer 2

The oxidation number of hydrogen increases to +1 while the oxidation number of iodine decreases to -1.

We must recall that the oxidation number of a particular atom or ion in any chemical specie is decided based on some arbitrary rules. Those rules are used to tell what the correct oxidation number of an atom should be in a compound or ion.

Firstly, the oxidation number of iodine and oxygen in the gas molecules is zero. The oxidation number of substances is not constant. However, on the right hand side, the oxidation number of hydrogen increases to +1 while the oxidation number of iodine decreases to -1.

Learn more: https://brainly.com/question/1445383