/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 90 Specify which of the following e... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 4: Problem 90

Specify which of the following equations represent oxidation鈥� reduction reactions, and indicate the oxidizing agent, the reducing agent, the species being oxidized, and the species being reduced a. \(\mathrm{CH}_{4}(g)+\mathrm{H}_{2} \mathrm{O}(g) \rightarrow \mathrm{CO}(g)+3 \mathrm{H}_{2}(g)\) b. \(2 \mathrm{AgNO}_{3}(a q)+\mathrm{Cu}(s) \rightarrow \mathrm{Cu}\left(\mathrm{NO}_{3}\right)_{2}(a q)+2 \mathrm{Ag}(s)\) c. \(\mathrm{Zn}(s)+2 \mathrm{HCl}(a q) \rightarrow \mathrm{ZnCl}_{2}(a q)+\mathrm{H}_{2}(g)\) d. \(2 \mathrm{H}^{+}(a q)+2 \mathrm{CrO}_{4}^{2-}(a q) \rightarrow \mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}(a q)+\mathrm{H}_{2} \mathrm{O}(l)\)

Short Answer

Expert verified
The redox reactions are a, b, and c. The oxidizing and reducing agents are: a. Oxidizing agent: Water; Reducing agent: Methane b. Oxidizing agent: Silver nitrate; Reducing agent: Copper c. Oxidizing agent: Hydrochloric acid; Reducing agent: Zinc

Step by step solution

01

Identify oxidation-reduction (redox) reactions

For each equation, assign oxidation numbers to the elements. If the oxidation numbers change from reactants to products, the equation is a redox reaction. a. \(CH_4(g)+H_2O(g) \rightarrow CO(g)+3H_2(g)\) - Assign oxidation numbers: C: -4 to +2, H: +1 to 0, O: -2 - Oxidation numbers change, so this is a redox reaction. b. \(2AgNO_3(aq)+Cu(s) \rightarrow Cu(NO_3)_2(aq)+2Ag(s)\) - Assign oxidation numbers: Ag: +1 to 0, N: +5, O: -2, Cu: 0 to +2 - Oxidation numbers change, so this is a redox reaction. c. \(Zn(s)+2HCl(aq) \rightarrow ZnCl_2(aq)+H_2(g)\) - Assign oxidation numbers: Zn: 0 to +2, H: +1 to 0, Cl: -1 - Oxidation numbers change, so this is a redox reaction. d. \(2H^+(aq)+2CrO_4^{2-}(aq) \rightarrow Cr_2O_7^{2-}(aq)+H_2O(l)\) - Assign oxidation numbers: H: +1, Cr: +6 to +6, O: -2 - Oxidation numbers do not change, so this is not a redox reaction.
02

Determine oxidizing and reducing agents

For each redox reaction, identify the species that cause the oxidation and reduction by determining which species gained or lost electrons. a. \(CH_4(g)+H_2O(g) \rightarrow CO(g)+3H_2(g)\) - Oxidation: C is oxidized from -4 to +2 (loses electrons) - Reduction: H is reduced from +1 to 0 (gains electrons) - Oxidizing agent: Water - Reducing agent: Methane b. \(2AgNO_3(aq)+Cu(s) \rightarrow Cu(NO_3)_2(aq)+2Ag(s)\) - Oxidation: Cu is oxidized from 0 to +2 (loses electrons) - Reduction: Ag is reduced from +1 to 0 (gains electrons) - Oxidizing agent: Silver nitrate - Reducing agent: Copper c. \(Zn(s)+2HCl(aq) \rightarrow ZnCl_2(aq)+H_2(g)\) - Oxidation: Zn is oxidized from 0 to +2 (loses electrons) - Reduction: H is reduced from +1 to 0 (gains electrons) - Oxidizing agent: Hydrochloric acid - Reducing agent: Zinc
03

Summary

The redox reactions are a, b, and c. The oxidation and reduction species, along with their corresponding agents, are as follows: a. Oxidizing agent: Water; Reducing agent: Methane b. Oxidizing agent: Silver nitrate; Reducing agent: Copper c. Oxidizing agent: Hydrochloric acid; Reducing agent: Zinc

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Oxidizing Agent
An oxidizing agent, also known as an oxidant, is a substance that causes another substance to lose electrons. In other words, it facilitates the process of oxidation by itself gaining electrons. This can seem a bit counterintuitive at first because although it "oxidizes" another component, it is actually reduced in the reaction. In the examples provided, the oxidizing agents are:
  • Water (\(H_2O\)) in the reaction with methane (\(CH_4\)).
  • Silver nitrate (\(AgNO_3\)) in the reaction with copper (\(Cu\)).
  • Hydrochloric acid (\(HCl\)) in the reaction with zinc (\(Zn\)).
The role of an oxidizing agent is crucial in redox reactions as it allows for the transfer of electrons. Recognizing the oxidizing agent in a reaction can involve tracking the change in oxidation numbers, which indicate gain of electrons.
Reducing Agent
The reducing agent, or reductant, is the opposite of the oxidizing agent. It is the species that donates electrons and reduces another species. While it reduces the other substance, it gets oxidized itself. Identifying the reducing agent helps to understand who gives up electrons in a chemical reaction. Here are the reducing agents from the provided reactions:
  • Methane (\(CH_4\)) donates electrons to water (\(H_2O\)).
  • Copper (\(Cu\)) donates electrons to silver nitrate (\(AgNO_3\)).
  • Zinc (\(Zn\)) donates electrons to hydrochloric acid (\(HCl\)).
In these reactions, the atoms of the reducing agents increase their oxidation numbers, highlighting their role in electron donation.
Oxidation Numbers
Oxidation numbers (or states) provide a simple way to keep track of electrons in a compound, permitting the identification of oxidizing or reducing agents without guessing. Here's how they change in each example:
  • In the reaction with methane, carbon changes from an oxidation number of -4 to +2, while hydrogen changes from +1 to 0. This show carbon's loss and hydrogen's gain of electrons.
  • For copper and silver nitrate, copper changes from 0 to +2, and silver changes from +1 to 0, revealing electron transfer between copper and silver.
  • In zinc's reaction with hydrochloric acid, zinc changes from 0 to +2 and hydrogen changes from +1 to 0, indicating zinc's electrons going to hydrogen.
Oxidation numbers are crucial for identifying redox reactions and understanding how electrons shift between species. By monitoring how these numbers change, chemists can decode complex reactions and predict product outcomes.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

You made 100.0 mL of a lead(II) nitrate solution for lab but forgot to cap it. The next lab session you noticed that there was only 80.0 mL left (the rest had evaporated). In addition, you forgot the initial concentration of the solution. You decide to take 2.00 mL of the solution and add an excess of a concentrated sodium chloride solution. You obtain a solid with a mass of 3.407 g. What was the concentration of the original lead(II) nitrate solution?

What mass of solid AgBr is produced when 100.0 \(\mathrm{mL}\) of 0.150 \(\mathrm{MAgNO}_{3}\) is added to 20.0 \(\mathrm{mL}\) of 1.00 \(\mathrm{M} \mathrm{NaBr} ?\)

Assign oxidation states for all atoms in each of the following compounds. a. \(\mathrm{UO}_{2}^{2+} \quad \quad f. \mathrm{Mg}_{2} \mathrm{P}_{2} \mathrm{O}_{7}\) b. \(\mathrm{As}_{2} \mathrm{O}_{3} \quad \quad g. \mathrm{Na}_{2} \mathrm{P}_{2} \mathrm{O}_{3}\) c. \(\mathrm{NaBiO}_{3} \quad h. \mathrm{Hg}_{2} \mathrm{Cl}_{2}\) d. \(\mathrm{As}_{4} \quad\quad \quad i. \mathrm{Ca}\left(\mathrm{NO}_{3}\right)_{2}\) e. \(\mathrm{HAsO}_{2}\)

A solution of permanganate is standardized by titration with oxalic acid \(\left(\mathrm{H}_{2} \mathrm{C}_{2} \mathrm{O}_{4}\right) .\) It required 28.97 \(\mathrm{mL}\) of the permanganate solution to react completely with 0.1058 g of oxalic acid. The unbalanced equation for the reaction is $$\mathrm{MnO}_{4}^{-}(a q)+\mathrm{H}_{2} \mathrm{C}_{2} \mathrm{O}_{4}(a q) \stackrel{\mathrm{Acidic}}{\longrightarrow} \mathrm{Mn}^{2+}(a q)+\mathrm{CO}_{2}(g)$$ What is the molarity of the permanganate solution?

Consider the reaction of 19.0 g of zinc with excess silver nitrite to produce silver metal and zinc nitrite. The reaction is stopped before all the zinc metal has reacted and 29.0 g of solid metal is present. Calculate the mass of each metal in the 29.0-g mixture
See all solutions

Recommended explanations on Chemistry Textbooks

Organic Chemistry

Read Explanation

Chemical Reactions

Read Explanation

Chemical Analysis

Read Explanation

Nuclear Chemistry

Read Explanation

Physical Chemistry

Read Explanation

Inorganic Chemistry

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.