Oxidation-Reduction Reactions Quiz

What is the oxidation state of chromium in the Na2Cr2O7 compound?

In the redox reaction H2(g) + ½ O2(g) → H2O(l), which substance acts as the reducing agent?

What is the total charge of the sulfate anion, SO4?

Which of the following statements about the Activity Series is true?

What occurs to the reducing agent during a redox reaction?

What is the oxidation state of sulfur in the sulfate ion (SO4)?

Which of the following is a characteristic of redox reactions?

Which metal is found lower than hydrogen in the Activity Series?

What is the oxidation number of sulfur in CdS?

In the reaction Mg(s) + 2 HCl(aq) → MgCl2(aq) + H2(g), what is oxidized?

Which of the following correctly identifies the reducing agent in the reaction between magnesium and hydrochloric acid?

What is the oxidation state of hydrogen in AlH3?

What is the total charge of the polyatomic ion S2O32-?

In the compound Na2Cr2O7, what is the oxidation number of chromium?

What type of reaction occurs when magnesium reacts with hydrochloric acid?

What is the oxidation number of oxygen in peroxides?

Oxidation-Reduction Reactions (Redox)

Redox reactions involve the transfer of electrons between reactants
Oxidation is the loss of electrons
Reduction is the gain of electrons
The substance causing oxidation is the oxidizing agent
The substance causing reduction is the reducing agent
Oxidizing agent is reduced
Reducing agent is oxidized

Assigning Oxidation Numbers

Elemental form: Oxidation number of 0
Monatomic ion: Oxidation number equals the charge
Polyatomic ion/molecule: Oxidation number same as if it were a monatomic ion
Hydrogen: +1 when bonded to a nonmetal, -1 when bonded to a metal
Oxygen: Usually -2, except in peroxides (-1) or bonded to a more electronegative element
Halogens: Usually -1, except when bonded to oxygen or fluorine (positive oxidation number)
Sum of oxidation numbers: 0 for neutral compounds, equal to the total charge for a polyatomic ion

Activity Series

The Activity Series ranks metals by their reactivity
Higher metals are more reactive, more easily lose electrons, and more readily oxidized
Metals higher than Hydrogen in the Activity Series will react with acids to form hydrogen gas
More reactive metals react vigorously with cold water
Gold is very unreactive and low in the Activity Series and will not react with simple acids

Test your understanding of oxidation and reduction reactions. This quiz covers key concepts such as electron transfer, assigning oxidation numbers, and the activity series of metals. Expand your knowledge on how these fundamental reactions play a crucial role in chemistry.