12.5g石灰石放入36.5g稀鹽酸中,恰好完全反應(yīng),同時放出4.4gCO2氣體.求石灰石中CaCO3的質(zhì)量分數(shù)

化學(xué)人氣：283 ℃時間：2019-10-18 08:43:11

優(yōu)質(zhì)解答

設(shè)有x克CaCO3
CaCO3+2HCL=CaCL2+H2O+CO2↑
100 44
x 4.4
100/x=44/4.4
x=10
所以mCaCO3%=10g/12.5g=80%稀鹽酸中溶質(zhì)的質(zhì)量分數(shù)反應(yīng)后所得溶液中溶質(zhì)的質(zhì)量分數(shù)。（結(jié)果保留一位小數(shù)）設(shè)有x克CaCO3 ygHCLzgCaCL2CaCO3+2HCL=CaCL2+H2O+CO2↑10073111 44xyZ4.4100/x=44/4.4=73/y =111/Zx=10y=7.3Z=11.1所以mCaCO3%=10g/12.5g=80% mHCL%=7.3g/36.5g=20%CaCL2%=11.1g/12.5g+36.5g-4.4g=25.6%