Silver sulfadiazine burn$-$treating cream creates a barrier against bacterial invasion and releases antimicrobial agents directly into the wound. If $25\mathrm{.}0$gAg$2$O reacts with $50\mathrm{.}0$gC$\_(10)$H$\_(10)$N$\_(4)$SO$\_(2),$ what mass of silver sulfadiazine, AgC$\_(10)$H$\_(9)$N$\_(4)$SO$\_(2),$ can be produced, assuming $84\%$ yield? What mass of which reagent is left unreacted