Gọi CTDC: RO
PTHH: RO+ 2HCl----->RCl2+H2O
Ta có
mdd\(_{HCl}=100.1,2=120\left(g\right)\)
m\(_{HCl}=\)\(\frac{120.21,9}{100}=26,28\left(g\right)\)
n\(_{HCl}=\frac{26,28}{36,5}=0,72\left(mol\right)\)
Theo PTHH: n\(_{RO}=\frac{1}{2}n_{HCl}=0,36\left(mol\right)\)
M\(_{RO}=\frac{17,8}{0,36}=49\left(g\right)\)
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