The compound $\mathrm{YBa}_{2} \mathrm{Cu}_{3} \mathrm{O}_{7}$, which shows superconductivity, has c

Question

The compound $\mathrm{YBa}_{2} \mathrm{Cu}_{3} \mathrm{O}_{7}$, which shows superconductivity, has copper in oxidation state $\frac{m}{n}$ {Fraction in the lowest form. Assume that the rare earth element yttrium is in its usual +3 oxidation state). Find m+n\

Professor PC Thomas Classes · Answer

$(+7 / 3)$ : Let the oxidation state of Cu be $x$, then we have, $$ +3+2 	imes(+2)+3 	imes x+7 	imes(-2)=0 $$ or $+3+4+3 x-14=0$\ or $3 x=14-3-4$\ or $x=+7 / 3$\