Oxidation states of oxygen - Chemistry Stack Exchange most recent 30 from chemistry.stackexchange.com 2019-09-18T03:23:13Z https://chemistry.stackexchange.com/feeds/question/60961 https://creativecommons.org/licenses/by-sa/4.0/rdf https://chemistry.stackexchange.com/q/60961 1 Oxidation states of oxygen Gourabo https://chemistry.stackexchange.com/users/28944 2016-10-15T06:33:08Z 2019-01-28T08:36:43Z <p>I'm given a question:</p> <blockquote> <p>Oxidation number of $\ce{O}$ in $\ce{BaO2}$ is $x$ and in $\ce{OF2}$ is $y$; then the value of $x+y$ is what?</p> </blockquote> <p>Now my main question is that if $\ce{F}$ has $-1$ valency in $\ce{OF2}$ then $\ce{O}$ must have valency of $+2$. But is that possible since $\ce{O}$ mainly has oxidation states of $-1$ &amp; $-2$ or am I making any mistake?</p> https://chemistry.stackexchange.com/questions/60961/-/60965#60965 8 Answer by Vidyanshu Mishra for Oxidation states of oxygen Vidyanshu Mishra https://chemistry.stackexchange.com/users/34347 2016-10-15T07:26:00Z 2016-11-29T00:49:59Z <p>The concept of oxidation state simply works on concept of electronegativity.The more electronegative atom acquire a negative charge while less electronegative atom acquire a positive charge. Depending on this hypothesis oxygen have 5 oxidation states.</p> <ol> <li><p>In all the oxides,oxygen has an oxidation state of $-2$. Eg. $\ce{CO2,CO}$</p></li> <li><p>In all peroxides (oxygen-oxygen linkage), oxygen has an oxidation state of $-1$. For example, consider $\ce{H2O2}$, here $\ce{H}$ is less electronegative so it will acquire a charge of $+1$ and to balance the $2$ positive charge of 2 H-atoms,each oxygen atom will acquire a charge of $-1$.</p></li> <li><p>In all superoxides ($\ce{KO2,CsO2,RbO2}$), oxygen has an oxidation state of $-\frac{1}{2}$,this is because $\ce{K,Cs,Rb}$, being elements of the first group and less electronegative than oxygen acquire a charge of $+1$, to balance it, each oxygen atom acquires a charge of $-\frac{1}{2}$.</p></li> <li><p>In one of the exceptions $\ce{OF2}$, the fluorine being more electronegative acquires a charge of $-1$ and to balance the $-2$ charge of 2 fluorine atoms oxygen acquires a charge of $+2$.</p></li> <li><p>As last, there is $\ce{O2F2}$, similarly here to balance the $-2$ charge on 2 $\ce{F}$-atoms each oxygen atom acquire a charge of $+1$.</p></li> </ol> https://chemistry.stackexchange.com/questions/60961/-/108680#108680 1 Answer by M Mrksa for Oxidation states of oxygen M Mrksa https://chemistry.stackexchange.com/users/71327 2019-01-28T06:10:26Z 2019-01-28T08:28:46Z <p>Oxygen can have 6 different oxidation states. Which oxidation state oxygen is in depends on which element oxygen is bonded to and what ratio the two elements are at:</p> <ul> <li>-2: This occurs in oxides e.g. <span class="math-container">$\ce{OsO4}$</span> and <span class="math-container">$\ce{RuO4}$</span></li> <li>-1: This occurs in peroxides e.g. <span class="math-container">$\ce{H2O2}$</span> </li> <li>-0.5: This occurs in superoxides e.g. compounds that contain the <span class="math-container">$\ce{O^-2}$</span> ion such as <span class="math-container">$\ce{KO2}$</span> </li> <li>0: This occurs in <span class="math-container">$\ce{O2}$</span></li> <li>+1: This occurs in <span class="math-container">$\ce{O2F2}$</span> as <span class="math-container">$2 \cdot -1+2 \cdot 1=0$</span> and fluorine has a greater electronegativity than oxygen.</li> <li>+2: This occurs in <span class="math-container">$\ce{OF2}$</span> as <span class="math-container">$+2+2 \cdot -1=0$</span></li> </ul> https://chemistry.stackexchange.com/questions/60961/-/108683#108683 0 Answer by Oscar Lanzi for Oxidation states of oxygen Oscar Lanzi https://chemistry.stackexchange.com/users/17175 2019-01-28T08:36:43Z 2019-01-28T08:36:43Z <p>There can also be a <span class="math-container">$0$</span> oxidation state in compounds, not just elemental oxygen. <a href="https://en.m.wikipedia.org/wiki/Hypofluorous_acid" rel="nofollow noreferrer">Hypofluorous acid</a> is known. This molecule with the structural formula <span class="math-container">$\ce{H - O - F}$</span> has (in the oxidation state formalism) oxygen gaining an electron from hydrogen but losing one to fluorine.</p>