Question

< Worksheets redox practice.doc Oxidation and Reduction Practice In each of the following equations, indicate the element that has been oxidized and the one that has been reduced. You should also label the oxidation state of each before and after the process: 1) 2 Na + FeCl, à 2 NaCl + Fe 2) 2 CH2 +50à 4 CO2 + 2H2O 3) 2 PbS + 30, à 2 SO2 + 2 PbO 4) 2H2 + O, à 2 H,0 5) Cu + HNO, à CUNO, + H 6) AgNO, + Cu à CUNO, + Ag

Answer 1

Oxidation is the process of addition of electronegative element or oxygen while reduction is defined as the addition of electropositive element or hydrogen or removal of electronegative element.

Oxidation number increases during oxidation while it decreases during reduction.

No ty te is reduced + Feeda ant ad the - Na gol oxidined Oxidation state Before process Na=0 Fe = +2 Afterprocess Na=t Fe= 0 2 2 CH +502 o is reduced 2 CH2 +50 400 + 2H₂0 c is oxidised ondation state Before process c un lato -- After process c = +4 = -2 Oxygen is reduced 3) Pbs + 30% - &502 + 3PbO 25027 Sulphuri, oxudised Oxidation state Before proces ter process s=-2 s=ty 0 0 0 = -2 o u reduced 4) 24, + og -210 His oxidised Oxidation state After process Before process H = +1 0 = 0 0= -2 His reduced 5) Cu + HNO3 - CuNoz the Tu is onidised oxidation state Before process Cu = 0 After process Cat l= 0 Hati

Cu is oxidised 6) AgNoz & Cu Cu Noz & Ag . Ag is reduced Oxidation state Before process Ag = + Cu ² O After Process =t