Consider this reaction occurring at 298 K: N2O( g) + NO2( g) ⇌ 3 NO( g) b. If a reaction mixture contains only N2O and NO2 at partial pressures of 1.0 atm each, the reaction will be spontaneous until some NO forms in the mixture. What maximum partial pressure of NO builds up before the reaction ceases to be spontaneous?

Video transcript

Hi everyone here we have a question telling us that the following reaction is spontaneous until some product is formed. Chlorine gas is plus two oxygen gashes forms to chlorine dioxide gashes. If one atmosphere of chlorine and one atmosphere of oxygen are mixed, what is the maximum partial pressure of chlorine dioxide produced when the reaction stops being spontaneous? So the reaction will no longer be spontaneous when Q equals K. So K. Equals the pressure of carbon dioxide squared, divided by the pressure of chlorine. Times the pressure of oxygen squared. So first we need to calculate our free energy, so our change in free energy is going to equal the change in energy of the product, minus the change in energy of the reactant. So our change in free energy equals two moles of chlorine dioxide Times 120 0. minus one mole of chlorine. Time zero plus one more of oxygen. Time zero, Which equals 241 killer jewels. Now we need to calculate R. K. So our change in free energy equals are negative gas constant times temperature, times the natural log of K. So okay equals E. To the negative change in free energy divided by r gas, constant times temperature. So that equals E. To the negative killed Jules, Times one times 10 to the third jewels Divided by one killer jewel divided by 8. jules per mole times killed in Times 298.15 kelvin and that equals 5.974. 2 times To the -43. Now we need to calculate our pressure so our K. Equals the pressure of chlorine dioxide squared, divided by our pressure of chlorine. Times are pressure of oxygen, So 5.974, 2 Times 10 to the equals our pressure of chlorine dioxide squared, divided by one times one. So our pressure of chlorine dioxide equals the square root of five .974, 2 Times 10 to the -43, Which equals 7.72, 9 Times 10 to the -22 Atmospheres. And we're going to round that to 7.7 times to the -22 atmospheres. And that is our final answer. Thank you for watching. Bye.