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 is the oxidation state of aluminum in $Al_2O_3$?

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

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

Answer: $Cu^{2+}$. $Cu^{2+}$ gains electrons and gets reduced.

Flashcard 3: Define 'redox reaction'.

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

Flashcard 4: 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 5: What is reduction in a redox reaction?

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

Flashcard 6: 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 7: Identify the reducing agent: $Zn + Cu^{2+} \rightarrow Zn^{2+} + Cu$.

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

Flashcard 8: 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 9: 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 10: What is the sum of oxidation states in an ion?

Answer: Charge of the ion. The sum equals the ion's overall charge.

Flashcard 11: State the oxidation state of chlorine in $Cl_2$.

Answer:

1. Diatomic chlorine is in its elemental state.

Flashcard 12: What is the oxidation state of oxygen in most compounds?

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

Flashcard 13: What happens to the oxidation state of an element during reduction?

Answer: Decreases. Reduction involves gain of electrons.

Flashcard 14: Describe a redox reaction in terms of electron transfer.

Answer: Electrons transfer from reducing to oxidizing agent. One species loses electrons while another gains them.

Flashcard 15: 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 16: What is the role of the reducing agent in a redox reaction?

Answer: Donates electrons. It loses electrons and gets oxidized itself.

Flashcard 17: What is the oxidation state of nitrogen in $NH_3$?

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

Flashcard 18: Identify the oxidizing agent in the reaction: $2H_2 + O_2 \rightarrow 2H_2O$.

Answer: $O_2$. $O_2$ gains electrons, so it's the oxidizing agent.

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 phosphorus in $PCl_5$?

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

Flashcard 21: Find the oxidation state of nitrogen in $NO_3^-$.

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

Flashcard 22: What is reduction in a redox reaction?

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

Flashcard 23: State the oxidation state of chlorine in $NaCl$.

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

Flashcard 24: Find the oxidation state of nitrogen in $NO_3^-$.

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

Flashcard 25: 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 26: What is the role of the oxidizing agent in a redox reaction?

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

Flashcard 27: Identify the reducing agent: $Zn + Cu^{2+} \rightarrow Zn^{2+} + Cu$.

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

Flashcard 28: What is the role of the oxidizing agent in a redox reaction?

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

Flashcard 29: Define 'redox reaction'.

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

Flashcard 30: State the oxidation state of chlorine in $NaCl$.

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

Flashcard 31: What is the oxidation state of carbon in $CH_4$?

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

Flashcard 32: 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 33: 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 34: Identify the element reduced: $2K + Br_2 \rightarrow 2KBr$.

Answer: $Br_2$. Bromine's oxidation state decreases from 0 to -1.

Flashcard 35: What happens to the oxidation state of an element during oxidation?

Answer: Increases. Oxidation involves loss of electrons.

Flashcard 36: What is the oxidation state of sulfur in $SO_2$?

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

Flashcard 37: In $H_2O_2$, what is the oxidation state of oxygen?

Answer: -1. In peroxide, oxygen has unusual -1 oxidation state.

Flashcard 38: Identify the element oxidized: $2K + Br_2 \rightarrow 2KBr$.

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

Flashcard 39: What is the oxidation state of carbon in $CO_2$?

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

Flashcard 40: Identify the element oxidized: $2K + Br_2 \rightarrow 2KBr$.

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

Flashcard 41: Find the oxidation state of chromium in $Cr_2O_7^{2-}$.

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

Flashcard 42: 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 43: Define the term 'disproportionation reaction'.

Answer: A single element undergoes both oxidation and reduction. Same element has atoms with different oxidation states.

Flashcard 44: 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 45: What happens to the oxidation state of an element during oxidation?

Answer: Increases. Oxidation involves loss of electrons.