`#Ly`
$a)$
`m_(\text{giảm}` `=` `80-72,32=7,68` $(g)$
PTHH: $CuO$ $+$ $H_2$ $\xrightarrow[]{t^o}$ $Cu$ $+$ $H_2O$
`Δ_M` `=` `80-64=16` $(g/mol)$
Tăng giảm khối lượng:
`n_(CuO(pư)` `=` `(7,68)/(16)=0,48` $(mol)$
Theo PT: `n_(H_2(pư)` `=` `n_(CuO(pư)` `=` `0,48` $(mol)$
`n_(H_2(bđ)` `=` `0,48:75%=0,64` $(mol)$
`->` `V_(H_2` `=` `0,64.22,4=14,336` $(l)$
$b)$
PTHH: $Zn$ $+$ $2HCl$ `->` $ZnCl_2$ $+$ $H_2$
Theo PT: `n_(Zn` `=` `n_(H_2` `=` `0,64` $(mol)$
`m_(Zn` `=` `0,64.65=41,6` $(g)$