AP Chemistry Flashcards: Oxidation Reduction Redox Reactions

What this deck covers

This deck focuses on Oxidation Reduction Redox Reactions, giving you a quick way to review the definitions, rules, and examples that matter most for AP Chemistry.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: What happens to the oxidation state of an element during oxidation?

Answer: Increases. Oxidation involves loss of electrons.

Flashcard 2: What is the oxidation state of sulfur in $H_2SO_4$?

Answer: +6. Calculate using: 2(+1) + S + 4(-2) = 0, so S = +6.

Flashcard 3: Identify the element reduced in the reaction: $Fe + CuSO_4 \rightarrow FeSO_4 + Cu$.

Answer: $Cu$. Copper's oxidation state decreases from +2 to 0.

Flashcard 4: What is the role of the oxidizing agent in a redox reaction?

Answer: Accepts electrons. It gains electrons and gets reduced itself.

Flashcard 5: Identify the element oxidized: $2K + Br_2 \rightarrow 2KBr$.

Answer: $K$. Potassium's oxidation state increases from 0 to +1.

Flashcard 6: What is the oxidation state of aluminum in $Al_2O_3$?

Answer: +3. Calculate using: 2(Al) + 3(-2) = 0, so Al = +3.

Flashcard 7: Define 'redox reaction'.

Answer: A reaction involving electron transfer. Involves oxidation and reduction occurring simultaneously.

Flashcard 8: Identify the reducing agent in the reaction: $2H_2 + O_2 \rightarrow 2H_2O$.

Answer: $H_2$. $H_2$ loses electrons, so it's the reducing agent.

Flashcard 9: Identify the reducing agent: $Zn + Cu^{2+} \rightarrow Zn^{2+} + Cu$.

Answer: $Zn$. $Zn$ loses electrons and gets oxidized.

Flashcard 10: Find the oxidation state of nitrogen in $NO_3^-$.

Answer: +5. Calculate using: N + 3(-2) = -1, so N = +5.

Flashcard 11: What is reduction in a redox reaction?

Answer: Gain of electrons. Reduction involves gaining electrons from another species.

Flashcard 12: What is the oxidation state of phosphorus in $H_3PO_4$?

Answer: +5. Calculate using: 3(+1) + P + 4(-2) = 0, so P = +5.

Flashcard 13: What is the oxidation state of carbon in $CO_2$?

Answer: +4. Calculate using: C + 2(-2) = 0, so C = +4.

Flashcard 14: What happens to the oxidation state of an element during reduction?

Answer: Decreases. Reduction involves gain of electrons.

Flashcard 15: State the oxidation state of chlorine in $Cl_2$.

Answer:

1. Diatomic chlorine is in its elemental state.

Flashcard 16: What is the oxidation state of nitrogen in $NH_3$?

Answer: -3. Calculate using: 3(+1) + N = 0, so N = -3.

Flashcard 17: What is the change in oxidation state for iron in $Fe_2O_3$ during reduction?

Answer: Decreases from +3 to 0. Reduction decreases oxidation state by gaining electrons.

Flashcard 18: What is the oxidation state of oxygen in most compounds?

Answer: -2. Oxygen typically has -2 oxidation state in compounds.

Flashcard 19: What is oxidation in a redox reaction?

Answer: Loss of electrons. Oxidation involves losing electrons to another species.

Flashcard 20: What is the oxidation state of sulfur in $SO_2$?

Answer: +4. Calculate using: S + 2(-2) = 0, so S = +4.

Flashcard 21: In redox terminology, what is a half-reaction?

Answer: Reaction showing either oxidation or reduction alone. Shows one part of the complete redox process.

Flashcard 22: What is the change in oxidation state for copper in $CuO$ during reduction?

Answer: Decreases from +2 to 0. Reduction decreases oxidation state by gaining electrons.

Flashcard 23: Identify the reducing agent in the reaction: $2H_2 + O_2 \rightarrow 2H_2O$.

Answer: $H_2$. $H_2$ loses electrons, so it's the reducing agent.

Flashcard 24: What is the role of the oxidizing agent in a redox reaction?

Answer: Accepts electrons. It gains electrons and gets reduced itself.

Flashcard 25: Identify the element oxidized: $2K + Br_2 \rightarrow 2KBr$.

Answer: $K$. Potassium's oxidation state increases from 0 to +1.

Flashcard 26: What is the oxidation state of sulfur in $H_2SO_4$?

Answer: +6. Calculate using: 2(+1) + S + 4(-2) = 0, so S = +6.

Flashcard 27: What happens to the oxidation state of an element during oxidation?

Answer: Increases. Oxidation involves loss of electrons.

Flashcard 28: State the oxidation state of chlorine in $NaCl$.

Answer: -1. Chlorine gains one electron to form chloride ion.

Flashcard 29: What is the oxidation state of carbon in $CH_4$?

Answer: -4. Calculate using: C + 4(+1) = 0, so C = -4.

Flashcard 30: Find the oxidation state of chromium in $Cr_2O_7^{2-}$.

Answer: +6. Calculate using: 2(Cr) + 7(-2) = -2, so Cr = +6.