\(a,C_{M\left(NaOH\right)}=\dfrac{0,3}{0,5}=0,6M\\ b,n_{NaOH}=\dfrac{24}{40}=0,6\left(mol\right)\\ C_{M\left(NaOH\right)}=\dfrac{0,6}{0,4}=1,5M\)

ai giúp mình với, đang cần gấp lắm ạ

\(n_{Cu^{2+}}=n_{SO_4^{2-}}=n_{CuSO_4}=0,5\left(mol\right)\)

\(\Rightarrow\left[Cu^{2+}\right]=\left[SO_4^{2-}\right]=\dfrac{0,5}{2}=0,25M\)

a, \(\left[Ca^{2+}\right]=\dfrac{0,15.0,5}{0,15+0,05}=0,375M\)

\(\left[Na^+\right]=\dfrac{0,05.2}{0,15+0,05}=0,5M\)

\(\left[Cl^-\right]=\dfrac{0,15.2.0,5+0,05.2}{0,15+0,05}=1,25M\)

b, \(\left[Fe^{3+}\right]=\dfrac{\dfrac{2.1,6}{400}}{1,5}\approx0,005M\)

\(\left[K^+\right]=\dfrac{\dfrac{2.6,96}{174}}{1,5}\approx0,053M\)

\(\left[SO_4^{2-}\right]=\dfrac{\dfrac{3.1,6}{400}+\dfrac{6,96}{174}}{1,5}\approx0,035M\)

\(n_{Na_2O}=\dfrac{12,4}{62}=0,2\left(mol\right)\\ Na_2O+H_2O\rightarrow2NaOH\\ n_{NaOH}=0,2.2=0,4\left(mol\right)\\ C_{MddNaOH}=\dfrac{0,4}{0,4}=1\left(M\right)\)

\(n_{Na_2O}=\dfrac{12,4}{62}=0,2mol\\ Na_2O+H_2O\rightarrow2NaOH\\ n_{NaOH}=0,2.2=0,4mol\\ C_{M_{NaOH}}=\dfrac{0,4}{0,4}=1M\)

$n_{BaCl_2} = \dfrac{41,6}{208} = 0,2(mol)$
$C_{M_{BaCl_2}} = 0,2 : 0,5 = 0,4M$

$BaCl_2 \to Ba^{2+} + 2Cl^-$

$[Ba^{2+}] = 0,4M ; [Cl^-] = 0,4.2 = 0,8M$

ai giúp mình với ạ 

$n_{HCl} = \dfrac{0,73}{36,5} = 0,02(mol)$

$HCl \to H^+ + Cl^-$
$[H^+] = [Cl^-] = C_{M_{HCl}} = \dfrac{0,02}{2} = 0,01M$

\(n_{Na_2CO_3}=\dfrac{2,12}{106}=0,02\left(mol\right)\\ C_{MddNa_2CO_3}=\dfrac{0,02}{2}=0,01\left(M\right)\)