OXIDATION,REDUCTION AND ELECTROLYSIS

What is a redox reaction? A redox reaction is a chemical reaction where oxidation and reduction occur simultaneously. What happens during oxidation in a redox reaction? Oxidation involves the loss of electrons by a substance. What happens during reduction in a redox reaction? Reduction involves the gain of electrons by a substance. What is the role of the oxidizing agent in a redox reaction? The oxidizing agent is the substance that gets reduced while causing another substance to be oxidized. What is the role of the reducing agent in a redox reaction? The reducing agent is the substance that gets oxidized while causing another substance to be reduced. How can you identify the oxidation number of an element in a compound? The oxidation number is determined based on a set of rules, such as assigning -2 to oxygen and +1 to hydrogen in most compounds. What is the oxidation state of oxygen in most compounds? The oxidation state of oxygen is usually -2. What is the oxidation state of hydrogen in most compounds? The oxidation state of hydrogen is usually +1. What is the sum of oxidation states in a neutral molecule? The sum of oxidation states in a neutral molecule is always zero. What is the sum of oxidation states in a polyatomic ion? The sum of oxidation states in a polyatomic ion equals the charge of the ion. What happens to the oxidation number of an element undergoing oxidation? The oxidation number increases during oxidation. What happens to the oxidation number of an element undergoing reduction? The oxidation number decreases during reduction. Why is the reaction between hydrogen and oxygen considered a redox reaction? It is a redox reaction because hydrogen is oxidized (loses electrons) and oxygen is reduced (gains electrons). What is the importance of redox reactions in biological systems? Redox reactions play a crucial role in energy production, such as in cellular respiration and photosynthesis. What is an example of a redox reaction in daily life? Combustion, such as the burning of fuels, is an example of a redox reaction. What happens to the electrons in a redox reaction? Electrons are transferred from one substance to another. How do you balance a redox reaction in acidic medium? By adding H+^+, H2_2O, and electrons to balance atoms and charges. How do you balance a redox reaction in basic medium? By adding OH−^-, H2_2O, and electrons to balance atoms and charges. What is a half-reaction in the context of redox reactions? A half-reaction represents either the oxidation or reduction part of a redox reaction. Why is the reaction between zinc and copper sulfate a redox reaction? Zinc is oxidized to Zn2+^{2+}, and Cu2+^{2+} is reduced to copper metal. How is corrosion of metals an example of a redox reaction? Corrosion involves the oxidation of metals, such as iron rusting due to exposure to oxygen and water. What is the role of redox reactions in electrochemical cells? Redox reactions generate electrical energy in electrochemical cells by transferring electrons through an external circuit. What is the difference between a galvanic cell and an electrolytic cell? A galvanic cell generates electricity from spontaneous redox reactions, while an electrolytic cell uses electricity to drive non-spontaneous redox reactions. What happens at the anode of a galvanic cell? Oxidation occurs at the anode of a galvanic cell. What happens at the cathode of a galvanic cell? Reduction occurs at the cathode of a galvanic cell. What is the standard electrode potential of a redox reaction? It is the potential difference measured under standard conditions when a half-cell is connected to the standard hydrogen electrode. How is the standard electrode potential related to the spontaneity of a redox reaction? A positive standard electrode potential indicates a spontaneous redox reaction. What is oxidation in terms of electron transfer? Loss of electrons. What is reduction in terms of electron transfer? Gain of electrons. What is the term for the substance that gets reduced in a redox reaction? Oxidizing agent. What is the term for the substance that gets oxidized in a redox reaction? Reducing agent. In the reaction 2Mg + O₂ → 2MgO, which element is oxidized? Magnesium. In the same reaction, which element is reduced? Oxygen. What is the oxidation state of oxygen in most compounds? -2. What is the oxidation state of hydrogen in most compounds? +1. What is the oxidation state of a free element like O₂ or N₂? 0. What happens to the oxidation state of an element during oxidation? It increases. What happens to the oxidation state of an element during reduction? It decreases. What is a redox reaction? A reaction in which both oxidation and reduction occur. In the reaction Zn + CuSO₄ → ZnSO₄ + Cu, which element is reduced? Copper. In the same reaction, which element is oxidized? Zinc. What type of substance donates electrons in a redox reaction? Reducing agent. What type of substance accepts electrons in a redox reaction? Oxidizing agent. What is the role of oxygen in most combustion reactions? It acts as the oxidizing agent. How can you identify the reducing agent in a redox reaction? It is the substance that loses electrons. How can you identify the oxidizing agent in a redox reaction? It is the substance that gains electrons. What is the oxidation number of chlorine in NaCl? -1. What is the oxidation number of sulfur in H₂SO₄? +6. What is the oxidation number of nitrogen in NH₃? -3. What is the oxidation number of carbon in CO₂? +4. Why are redox reactions important in biological systems? They are involved in processes like cellular respiration and photosynthesis. What happens to the electrons during a redox reaction? They are transferred from one species to another. How does the oxidation state of an atom change in a reducing agent? It increases.