16: Oxidation and Reduction
- Page ID
- 47430
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)The rusting of an old car. A burning campfire. A toy battery-operated car. The chemical processes in your body that break down carbohydrates to produce water, carbon dioxide and energy. The ripening of fruit. It's not easy to see what all of these types of reactions have in common, but they all belong to a very important category of chemical reactions known as oxidation-reduction (or redox) reactions.
- 16.2: Oxidation and Reduction- Some Definitions
- This page explains redox reactions, which involve the transfer of electrons where one substance loses electrons (oxidation) and another gains them (reduction). Originally, oxidation referred to substances combining with oxygen, while reduction involved refining metals. A demonstration with copper wire and silver nitrate shows copper oxidizing to form ions, while silver ions reduce to form solid silver crystals.
- 16.3: Oxidation States- Electron Bookkeeping
- This page covers redox reactions and the concept of oxidation numbers, which indicate electron transfer in compounds. It explains how electronegativity affects electron sharing, exemplified by water (H2O) and hydrogen peroxide (H2O2). Key rules for determining oxidation numbers are outlined, including that pure elements are zero and hydrogen is generally +1, while oxygen is typically -2.
- 16.4: Balancing Redox Equations
- This page covers the half-reaction method for balancing redox equations, highlighting the separation of oxidation and reduction processes. It details the steps to balance half-reactions for atoms and charge, ensuring electron loss and gain are equal. Examples include dealing with spectator ions and balancing water and H+ in acidic solutions. The page underscores the significance of mastering half-reactions in understanding electrochemistry and stresses the value of practice for improvement.
- 16.5: The Activity Series- Predicting Spontaneous Redox Reactions
- This page covers the activity series, ranking metals and nonmetals by reactivity and their ability to replace elements in single-replacement reactions. It highlights that a more reactive element displaces a less reactive one, illustrating with examples like sodium's reaction with water compared to silver. The page also includes specific predictions of reactions, such as nickel replacing lead but not iron, along with exercises for practicing reaction predictions.
- 16.6: Batteries- Using Chemistry to Generate Electricity
- This page covers oxidation-reduction (redox) reactions and their role in batteries, defining oxidation as electron loss and reduction as electron gain. It explains electrochemical cells with anodes and cathodes generating electricity through these reactions. The page distinguishes between primary (non-rechargeable) and secondary (rechargeable) batteries, including examples like dry cell and lead-acid batteries, and introduces fuel cells for direct energy conversion.
- 16.7: Electrolysis- Using Electricity to Do Chemistry
- This page covers electrolytic and electrochemical cells, highlighting the use of electrical energy to drive non-spontaneous reactions in electrolytic cells versus generating electricity from spontaneous reactions in electrochemical cells. It explains electrolysis, with examples like water and sodium chloride, discussing reduction and oxidation at electrodes. The significance of anodes and cathodes, alongside electroplating techniques, is also emphasized.
- 16.8: Corrosion- Undesirable Redox Reactions
- This page discusses the corrosion of metals, highlighting its economic impact and the process of electrochemical oxidation leading to rust formation in iron. Factors that accelerate corrosion, such as metal contact and saltwater exposure, are examined, with an example of the Statue of Liberty. It outlines prevention methods, including protecting metals from moisture, implementing cathodic protection with zinc or magnesium, and using corrosion-resistant alloys like stainless steel.