\(n_{ZnSO_4}=0,1mol\)
\(n_{NaOH}=0,4.0,75=0,3mol\)
ZnSO4+2NaOH\(\rightarrow\)Zn(OH)2\(\downarrow\)+Na2SO4
- Tỉ lệ: \(\dfrac{0,1}{1}=0,1< \dfrac{0,3}{2}=0,15\)\(\rightarrow\)ZnSO4 hết, NaOH dư
\(n_{NaOH\left(pu\right)}=2n_{ZnSO_4}=0,2mol\rightarrow n_{NaOH\left(dư\right)}=0,3-0,2=0,1mol\)
\(n_{Na_2SO_4}=n_{Zn\left(OH\right)_2}=n_{ZnSO_4}=0,1mol\)
2NaOH+Zn(OH)2\(\rightarrow\)Na2ZnO2+H2O
- Tỉ lệ:\(\dfrac{0,1}{2}=0,05< \dfrac{0,1}{1}=0,1\) \(\rightarrow\)NaOh hết, Zn(OH)2 dư
\(n_{Na_2ZnO_2\left(tt\right)}=n_{Zn\left(OH\right)_2\left(pu\right)}=\dfrac{1}{2}n_{NaOH}=\dfrac{0,1}{2}=0,05mol\)
\(n_{Zn\left(OH\right)_2\left(dư\right)}=0,1-0,05=0,05mol\)
m=0,05.99=4,95 gam
- Dung dịch sau phản ứng gồm: Na2SO4 0,1 mol, Na2ZnO2 0,05 mol
\(C_{M_{Na_2SO_4}}=\dfrac{0,1}{0,5}=0,2M\)
\(C_{M_{Na_2ZnO_2}}=\dfrac{0,05}{0,5}=0,1M\)