?$ $?設(shè)分解的過氧化氫質(zhì)量為?$x，$?
?$ {2\mathrm {H}_{2}\mathrm {O}_{2}\xlongequal{催化劑}2\mathrm {H}_{2}\mathrm {O} + \mathrm {O}_{2}↑}$?
68 32
?$x$ ? 0.32g
?$ \frac {68}{32}=\frac {x}{0.32\mathrm {g}}，$?解得?$x=0.68\mathrm {g}$?
?$ $?原過氧化氫質(zhì)量：?$20\mathrm {g}×15\%=3\mathrm {g}$?
?$ $?剩余過氧化氫質(zhì)量：?$3\mathrm {g} - 0.68\mathrm {g}=2.32\mathrm {g}$?
?$ $?答：溶液中剩余的?${\mathrm {H}_{2}\mathrm {O}_{2}}$?的質(zhì)量為?$2.32\mathrm {g}。$?
