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\(V_{\text{dd}}=200+250=450ml=0,45l\\ n_{H_2SO_4}=\left(0,2.1\right)+\left(2.0,25\right)=0,7\left(mol\right)\\ C_M=\dfrac{0,7}{0,45}=1,5M\)
a, \(n_{NaOH}=0,2.1=0,2\left(mol\right)\)
\(m_{NaOH}=0,2.40=8\left(g\right)\)
b, \(n_{H_2SO_4}=2.0,1=0,2\left(mol\right)\)
\(c,C\%=\dfrac{6}{200}.100\%=3\%\)
\(m_{NaCl}=\dfrac{200.8}{100}=16\left(g\right)\)
PTHH: \(Na_2SO_4+CaCl_2\rightarrow2NaCl+CaSO_4\downarrow\)
Ta có: \(\left\{{}\begin{matrix}n_{Na_2SO_4}=0,1\cdot0,5=0,05\left(mol\right)\\n_{CaCl_2}=0,1\cdot0,4=0,04\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\) Na2SO4 dư
\(\Rightarrow\left\{{}\begin{matrix}n_{CaSO_4}=0,04\left(mol\right)\\n_{NaCl}=0,08\left(mol\right)\\n_{Na_2SO_4\left(dư\right)}=0,01\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}m_{CaSO_4}=0,04\cdot136=5,44\left(g\right)\\C_{M_{NaCl}}=\dfrac{0,08}{0,1+0,1}=0,4\left(M\right)\\C_{M_{Na_2SO_4\left(dư\right)}}=\dfrac{0,01}{0,2}=0,05\left(M\right)\end{matrix}\right.\)
\(a,n_{H_2SO_4}=0,3.0,75+0,3.0,25=0,3\left(mol\right)\\ V_{ddH_2SO_4}=300+300=600\left(ml\right)=0,6\left(l\right)\\ \rightarrow C_{M\left(H_2SO_4\right)}=\dfrac{0,3}{0,6}=0,5M\\ m_{H_2SO_4}=0,3.98=29,4\left(g\right)\\ m_{ddH_2SO_4}=600.1,02=612\left(g\right)\\ \rightarrow C\%_{H_2SO_4}=\dfrac{29,4}{612}.100\%=4,8\%\)
\(b,\) Đặt kim loại M có hoá trị n (n ∈ N*)
PTHH: \(2M+nH_2SO_4\rightarrow M_2\left(SO_4\right)_n+nH_2\uparrow\)
\(\dfrac{0,6}{n}\)<---0,3--------------------------->0,3
\(\rightarrow M_M=\dfrac{5,4}{\dfrac{0,6}{n}}=9n\left(g\text{/}mol\right)\)
Vì n là hoá trị của M nên ta xét bảng
| \(n\) | \(1\) | \(2\) | \(3\) |
| \(M_M\) | \(9\) | \(18\) | \(27\) |
| \(Loại\) | \(Loại\) | \(Al\) |
Vậy M là Al
\(c,n_{KClO_3}=\dfrac{15,3125}{122,5}=0,125\left(mol\right)\)
PTHH:
\(2H_2+O_2\xrightarrow[]{t^o}2H_2O\)
0,3-->0,15
\(2KClO_3\xrightarrow[]{t^o}2KCl+3O_2\uparrow\)
0,1<---------------------0,15
\(\rightarrow H=\dfrac{0,1}{0,125}.100\%=80\%\)
\(n_{NaOH}=0.2\cdot0.5=0.1\left(mol\right)\)
\(n_{CuSO_4}=0.1\cdot2=0.2\left(mol\right)\)
\(2NaOH+CuSO_4\rightarrow Na_2SO_4+Cu\left(OH\right)_2\)
\(0.1.............0.05...............0.05...........0.05\)
\(m_{Cu\left(OH\right)_2}=0.05\cdot98=4.9\left(g\right)\)
\(C_{M_{Na_2SO_4}}=\dfrac{0.05}{0.2+0.1}=0.167\left(M\right)\)
\(C_{M_{CuSO_4\left(dư\right)}}=\dfrac{0.2-0.05}{0.1}=1.5\left(M\right)\)