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Đáp án C
n N a 2 S O 4 = 0,02 mol; nNaCl=0,5 mol; nNa+= 0,02.2+0,5= 0,54 mol
[Na+]= 0,54/(0,117+0,171+0,212)= 1,08M
`n_{BaCl_2}=200.10^{-3}.1=0,2(mol)`
`n_{KCl}=100.10^{-3}.2=0,2(mol)`
`->n_{Cl^-}=2n_{BaCl_2}+n_{KCl}=0,6(mol)`
`->[Cl^-]={0,6}/{(200+100).10^{-3}}=2M`
Bài 1:
Ta có: \(n_{OH^-}=n_{Na^+}=n_{NaOH}=0,2.0,4=0,08\left(mol\right)\)
\(n_{H^+}=n_{Cl^-}=n_{HCl}=0,4.0,3=0,12\left(mol\right)\)
PT ion: \(OH^-+H^+\rightarrow H_2O\)
_____0,08_____0,12 (mol)
⇒ nOH- (dư) = 0,04 (mol)
\(\Rightarrow\left\{{}\begin{matrix}\left[Na^+\right]=\frac{0,08}{0,6}\approx0,133M\\\left[Cl^-\right]=\frac{0,12}{0,6}=0,2M\\\left[OH^-\right]=\frac{0,04}{0,6}\approx0,066M\end{matrix}\right.\)
Câu 2:
Ta có: \(\Sigma n_{K^+}=n_{KCl}+2n_{K_2SO_4}=0,2.1,5+0,3.2.2=1,5\left(mol\right)\)
\(n_{Cl^-}=n_{KCl}=0,2.1,5=0,3\left(mol\right)\)
\(n_{SO_4^{2-}}=0,3.2=0,6\left(mol\right)\)
\(\Rightarrow\left\{{}\begin{matrix}\left[K^+\right]=\frac{1,5}{0,5}=3M\\\left[Cl^-\right]=\frac{0,3}{0,5}=0,6M\\\left[SO_4^{2-}\right]=\frac{0,6}{0,5}=1,2M\end{matrix}\right.\)
Bạn tham khảo nhé!
a, \(\left[Ca^{2+}\right]=\dfrac{0,15.0,5}{0,15+0,05}=0,375M\)
\(\left[Na^+\right]=\dfrac{0,05.2}{0,15+0,05}=0,5M\)
\(\left[Cl^-\right]=\dfrac{0,15.2.0,5+0,05.2}{0,15+0,05}=1,25M\)
a) Ta có: \(n_{Al\left(NO_3\right)_3}=\dfrac{4,26}{213}=0,02\left(mol\right)\) \(\Rightarrow\left\{{}\begin{matrix}n_{Al^+}=0,02\left(mol\right)\\n_{NO_3^-}=0,06\left(mol\right)\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}\left[Al^+\right]=\dfrac{0,02}{0,1}=0,2\left(M\right)\\\left[NO_3^-\right]=\dfrac{0,06}{0,1}=0,6\left(M\right)\end{matrix}\right.\)
b) Ta có: \(\left[Na^+\right]=0,1+0,02\cdot2+0,3=0,304\left(M\right)\)
c) Bạn xem lại đề !!
Câu 3 :
\(pH=-log\left[H^+\right]=-log\left(0.1\right)=1\)
Câu 4 :
Chứa các ion : H+ , Cl-
Câu 5 :
\(n_{NaOH}=n_{HCl}=0.02\cdot0.1=0.002\left(mol\right)\)
\(\Rightarrow x=\dfrac{0.002}{0.01}=0.2\left(M\right)\)
Câu 1 :
Bảo toàn điện tích :
\(n_{SO_4^{2-}}=\dfrac{0.2\cdot2+0.1-0.05}{2}=0.225\left(mol\right)\)
\(m_{Muối}=0.2\cdot64+0.1\cdot39+0.05\cdot35.5+0.225\cdot96=40.075\left(g\right)\)
Câu 2 :
\(\left[Na^+\right]=\dfrac{0.15\cdot0.5\cdot2+0.05\cdot1}{0.15+0.05}=1\left(M\right)\)
\(NaCl\rightarrow Na^++Cl^-\)
\(\left[Na^+\right]=\left[Cl^-\right]=0.1\left(M\right)\)