Redox Reaction NEET Questions: Answer Key, pdf
Redox Reaction NEET Questions cowl critical standards in oxidation-reduction procedures, specializing in electron switch, oxidation states, and balancing redox reactions. These questions test a candidate’s draw close at the mechanisms of redox reactions, common oxidizing and lowering marketers, and electrochemical principles. For NEET, gaining knowledge of redox reactions is essential as they’re foundational to understanding biochemical strategies and strength transfer in cells. Solving exercise questions enhances comprehension and prepares college students to address complex NEET chemistry troubles with a bit of luck.
- Introduction to Redox Reaction
- Download: Redox Reaction NEET Questions
- Types of Redox Reactions
- Oxidation Number and Its Calculation
- Balancing Redox Reactions
- Electrochemical Cells and Redox Reactions
- Redox Reactions in Everyday Life
- Tips and Strategies for Redox Reaction Questions in NEET
- Practice NEET Questions on Redox Reaction
- FAQs about Redox Reaction
Introduction to Redox Reaction
Redox reaction, concerning oxidation and discount techniques, are key principles in chemistry that seem regularly in NEET assessments. In these reactions, one substance loses electrons (oxidation) whilst every other profits electrons (discount), demonstrating critical ideas of electron transfer. Understanding redox reactions is vital for NEET aspirants, as those questions examine expertise in areas like balancing equations, oxidation states, and electrochemical cells. Mastery of those reactions aids in grasping broader chemistry topics, inclusive of metabolism in biochemistry and electrochemical applications. NEET questions on redox reactions test students’ analytical talents, regularly concerning calculations and conceptual programs. Regular practice with redox troubles equips college students to technique associated NEET questions hopefully, improving their readiness for the competitive exam.
Oxidation and Reduction Basics
- Oxidation: This entails the loss of electrons by a species. The oxidation number of the species increases.
Example: 2Na → 2Na⁺ + 2e⁻ (Sodium loses an electron, becoming oxidized)
- Reduction: This entails the gain of electrons by a species. The oxidation number of the species decreases.
Example: Cl₂ + 2e⁻ → 2Cl⁻ (Chlorine gains electrons, becoming reduced)
Oxidizing and Reducing Agents
- Oxidizing Agent: A substance that gains electrons (is reduced) and causes another substance to lose electrons (be oxidized).
Example: In the reaction 2Fe + 3Cl₂ → 2FeCl₃, chlorine (Cl₂) is the oxidizing agent because it gains electrons from iron.
- Reducing Agent: A substance that loses electrons (is oxidized) and causes another substance to gain electrons (be reduced).
Example: In the same reaction, iron (Fe) is the reducing agent because it loses electrons to chlorine.
- Mnemonic Device: A common mnemonic to remember the principles of oxidation and reduction is OIL RIG:
- Oxidation Is Loss (of electrons)
- Reduction Is Gain (of electrons)
Download: Redox Reaction NEET Questions
| Title | Download |
|---|---|
| Redox Reaction NEET Questions with Answer |
Types of Redox Reactions
| Type of Redox Reaction | General Equation | Example |
|---|---|---|
| Combination Reaction | A + B → AB | 2Mg(s) + O₂(g) → 2MgO(s) |
| Decomposition Reaction | AB → A + B | 2HgO(s) → 2Hg(l) + O₂(g) |
| Displacement Reaction | A + BC → AC + B | Zn(s) + CuSO₄(aq) → ZnSO₄(aq) + Cu(s) |
| Disproportionation Reaction | A + A → A⁺ + A⁻ | 2H₂O₂(l) → 2H₂O(l) + O₂(g) |
Oxidation Number and Its Calculation
Rules for Assigning Oxidation Numbers
- Elements in their elemental state: The oxidation quantity of an atom in its elemental kingdom is usually 0.
Example: H₂, O₂, Na, Cl₂
- Monatomic ions: The oxidation wide variety of a monatomic ion is equal to its price.
Example: Na⁺ (+1), Cl⁻ (-1), Mg²⁺ (+2)
- Fluorine: Fluorine constantly has an oxidation quantity of -1 in its compounds.
- Oxygen: Oxygen commonly has an oxidation variety of -2 in its compounds. Exceptions consist of peroxides (like H₂O₂) wherein it is -1 and superoxides in which it is -1/2.
- Hydrogen: Hydrogen normally has an oxidation range of +1 in its compounds. However, in metallic hydrides (like NaH), it’s -1.
- Group 1 elements: Always +1
- Group 2 factors: Always +2
- Group 17 elements: Usually -1
The sum of oxidation numbers in a neutral compound is zero.
The sum of oxidation numbers in a polyatomic ion is equal to the price of the ion.
Common Examples and Practice Problems
Example 1: Calculate the oxidation wide variety of sulfur in H₂SO₄.
- Hydrogen: +1 (2 atoms) = +2
- Oxygen: -2 (four atoms) = -8
- Let the oxidation quantity of sulfur be x.
- Sum of oxidation numbers = 0
- So, +2 + x – 8 = 0
- x = +6
Example 2: Determine the oxidation quantity of chromium in Cr₂O₇²⁻.
- Oxygen: -2 (7 atoms) = -14
- Let the oxidation quantity of each chromium atom be x.
- Sum of oxidation numbers = -2 (fee of the ion)
- So, 2x – 14 = -2
- x = +6
Practice Problem:
- What is the oxidation number of nitrogen in HNO₃?
- What is the oxidation range of manganese in KMnO₄?
Balancing Redox Reactions
| Method | Steps Involved |
|---|---|
| Oxidation Number Method | 1. Assign oxidation numbers to all atoms in the equation. 2. Identify the atoms that undergo a change in oxidation number. 3. Balance the change in oxidation numbers by adding appropriate coefficients. 4. Balance the remaining atoms by inspection. 5. Balance the charge by adding electrons. 6. Equalize the number of electrons gained and lost. 7. Combine the half-reactions and cancel out common terms. |
| Half-Reaction Method | 1. Write the oxidation and reduction half-reactions. 2. Balance atoms other than H and O. 3. Balance O atoms by adding H₂O. 4. Balance H atoms by adding H⁺. 5. Balance charge by adding electrons. 6. Equalize the number of electrons gained and lost. 7. Combine the half-reactions and cancel out common terms. 8. If the reaction is in basic solution, add OH⁻ ions to neutralize H⁺ ions. |
Electrochemical Cells and Redox Reactions
Galvanic Cells and Electrode Potential
A galvanic cell, also referred to as a voltaic cell, is an electrochemical cell that converts chemical energy into electric energy. It consists of half-cells:
- Anode: The electrode wherein oxidation occurs.
- Cathode: The electrode where reduction happens.
Electrode Potential:
- The potential difference between an electrode and the electrolyte solution.
- Measured in volts (V).
- It is a measure of the tendency of an electrode to gain or lose electrons.
Standard Electrode Potential (E°) and Nernst Equation
- Standard Electrode Potential (E°): The electrode potential measured under standard conditions (1 M concentration, 1 atm pressure, 298 K).
- Nernst Equation: Relates the electrode potential (E) to the standard electrode potential (E°), temperature (T), and the concentrations of the species involved in the redox reaction.
E = E° – (RT/nF) ln Q
Where:
- E: Electrode potential
- E°: Standard electrode potential
- R: Gas constant
- T: Temperature
- n: Number of electrons transferred
- F: Faraday’s constant
- Q: Reaction quotient
Applications in NEET Questions
NEET questions about electrochemical cells frequently involve:
- Calculating cell potential: Using the Nernst equation to determine the cell potential under various conditions.
- Identifying anode and cathode: Recognizing the oxidation and reduction half-reactions to identify the anode and cathode.
- Predicting spontaneity: Determining whether a redox reaction is spontaneous based on the cell potential.
- Understanding the electrochemical series: Using the electrochemical series to evaluate the reactivity of metals and predict the direction of redox reactions.
- Applications of electrochemical cells: Knowing the applications of batteries, fuel cells, and corrosion prevention.
Redox Reactions in Everyday Life
| Application | Redox Reaction Involved |
|---|---|
| Metabolism | Cellular respiration: Glucose is oxidized to produce energy, while oxygen is reduced to water. Photosynthesis: Water is oxidized to oxygen, while carbon dioxide is reduced to glucose. |
| Corrosion | Iron rusting: Iron is oxidized to iron oxide in the presence of oxygen and water. |
| Batteries | Lead-acid batteries: Lead is oxidized to lead sulfate, while lead oxide is reduced to lead sulfate. Lithium-ion batteries: Lithium ions are oxidized and reduced between the anode and cathode. |
| Combustion | Burning of fuels: Hydrocarbons are oxidized to carbon dioxide and water. |
| Bleaching | Chlorine bleach: Chlorine oxidizes colored compounds to colorless ones. |
| Photography | Development of film: Silver halide salts are reduced to metallic silver by a reducing agent. |
| Food Preservation | Canning: Food is oxidized by oxygen, leading to spoilage. Canning removes oxygen to prevent this. |
Tips and Strategies for Redox Reaction Questions in NEET
Common Pitfalls and How to Avoid Them
Confusion in Oxidation States:
- Practice: Regularly practice assigning oxidation numbers to elements in compounds and ions.
- Rules: Memorize the policies for assigning oxidation numbers, specifically for common elements like oxygen, hydrogen, and halogens.
- Visualize: Use diagrams or flowcharts to visualize the electron transfer technique.
Balancing Redox Reactions:
- Method Selection: Choose the technique (oxidation range method or half-response method) which you are most snug with.
- Step-by-Step Approach: Break down the balancing system into smaller steps.
- Check: Always double-test your balanced equation to make sure that atoms and charges are balanced on both aspects.
Electrochemical Cells:
- Identify Anode and Cathode: Clearly become aware of the anode (oxidation) and cathode (reduction) half of-cells.
- Nernst Equation: Understand the Nernst equation and how to apply it to calculate mobile potentials under non-trendy conditions.
- Electrochemical Series: Use the electrochemical series to predict the direction of redox reactions and the relative strengths of oxidizing and reducing retailers.
Quick Revision Tips for Last-Minute Prep
- Flashcards: Create flashcards with key principles, formulation, and examples.
- Mind Maps: Visualize the connections among unique topics.
- Practice Problems: Solve a variety of exercise problems to boost your knowledge.
- Review Notes: Go thru your notes and highlight vital points.
- Focus on Concepts: Understand the underlying standards as opposed to memorizing formulas.
Practice NEET Questions on Redox Reaction
| Question | Answer |
|---|---|
| 1. In the reaction, 2FeCl₂ + Cl₂ → 2FeCl₃, chlorine acts as: a) Oxidizing agent b) Reducing agent c) Catalyst d) Dehydrating agent | a) Oxidizing agent |
| 2. The oxidation number of sulfur in H₂SO₄ is: a) +2 b) +4 c) +6 d) +8 | c) +6 |
| 3. Which of the following is a redox reaction? a) NaCl + KNO₃ → NaNO₃ + KCl b) CaCO₃ → CaO + CO₂ c) 2HgO → 2Hg + O₂ d) BaCl₂ + H₂SO₄ → BaSO₄ + 2HCl | c) 2HgO → 2Hg + O₂ |
| 4. In a galvanic cell, the electrons flow from: a) Anode to cathode through the external circuit b) Cathode to anode through the external circuit c) Anode to cathode through the internal circuit d) Cathode to anode through the internal circuit | a) Anode to cathode through the external circuit |
| 5. The standard electrode potential for the reaction, Zn²⁺ + 2e⁻ → Zn is -0.76 V. This means that: a) Zinc is a strong oxidizing agent b) Zinc is a strong reducing agent c) Zinc ions are strong oxidizing agents d) Zinc ions are strong reducing agents | b) Zinc is a strong reducing agent |
FAQs about Redox Reaction
Q. What are redox reactions?
Ans: Redox reactions contain the transfer of electrons among materials, which includes oxidation (loss of electrons) and reduction (gain of electrons).
Q. Why are redox reactions crucial for NEET?
Ans: Redox reactions are key in biology and chemistry, helping college students understand cell respiration, photosynthesis, and various biochemical reactions important for NEET tests.
Q. What varieties of redox questions appear in NEET?
Ans: NEET questions may include identifying oxidizing/reducing agents, balancing redox reactions, and real-life applications, including in metabolism.
Q. How can I discover the oxidizing and reducing agents in a response?
Ans: The oxidizing agent gains electrons and undergoes reduction, whilst the reducing agent loses electrons and undergoes oxidation.
Q. What are a few brief suggestions for solving redox questions in NEET?
Ans: Balance atoms and charges systematically, consider common oxidation states, and practice half-reaction techniques for complex equations.