C_M (mol/l) chứ nhỉ đề cho mol rồi mà

\(a,C_{M\left(NaOH\right)}=\dfrac{n}{V}=\dfrac{0,2}{0,2}=1M\\ b,n_{HCl}=\dfrac{7,3}{36,5}=0,2\left(mol\right)\\ C_{M\left(HCl\right)}=\dfrac{n}{V}=\dfrac{0,2}{0,5}=0,4M\\ c,n_{NH_3}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\\ C_{M\left(NH_3\right)}=\dfrac{0,3}{0,3}=1M\\ d,n_{H_2SO_4}=\dfrac{4,9}{98}=0,05\left(mol\right)\\ C_{M\left(H_2SO_4\right)}=\dfrac{0,05}{0,25}=0,2M\)

\(a,m_{dd}=\dfrac{5}{12\%}=\dfrac{125}{3}\left(g\right)\\ b,m_{dd}=\dfrac{4}{7,3\%}=\dfrac{4000}{73}\left(g\right)\\ c,m_{NaOH}=0,5.40=20\left(g\right)\\ m_{dd}=\dfrac{20}{10\%}=200\left(g\right)\)

\(m_{\text{dd}}=\dfrac{5.100}{12}=41,6\left(g\right)\\ m_{\text{dd}}=\dfrac{4.100}{7,3}=\dfrac{4000}{73}\left(g\right)\\ m_{\text{dd}}=\dfrac{\left(0,5.40\right).100}{10}=200\left(g\right)\)

1) Dung dịch HCl gồm các ion H+ và Cl-

\(n_{H^+}=n_{HCl}\)

=> \(\left[H^+\right]=CM_{HCl}=0,02M\)

2)  Dung dịch NaCl gồm các ion Na+ và Cl-

\(n_{Na^+}=n_{NaCl}\)

=> \(\left[Na^+\right]=CM_{NaCl}=0,3M\)

Có lẽ bạn hiểu nhầm M (mol/l) với mol rồi :)

Sửa hết mol ---> M nha

\(a,n_{NaCl}=2,5.0,9=2,25\left(mol\right)\\ \rightarrow m_{NaCl}=2,25.58,5=131,625\left(g\right)\\ b,m_{MgCl_2}=\dfrac{4.50}{100}=2\left(g\right)\\ c,Đổi:250ml=0,25l\\ \rightarrow n_{MgSO_4}=0,1.0,25=0,025\left(mol\right)\\ \rightarrow m_{MgSO_4}=0,025.120=3\left(g\right)\\ d,m_{NaOH}=\dfrac{40.20}{100}=8\left(g\right)\)

a) \(n_{NaCl}=2,5.0,9=2,25\left(mol\right)\Rightarrow m_{NaCl}=2,25.58,5=131,625\left(g\right)\)

b) \(m_{MgCl_2}=\dfrac{50.4}{100}=2\left(g\right)\)

c) \(n_{MgSO_4}=0,25.0,1=0,025\left(mol\right)\Rightarrow m_{MgSO_4}=0,025.120=3\left(g\right)\)

d) \(m_{NaOH}=\dfrac{20.40}{100}=8\left(g\right)\)

\(n_{H_2}=\dfrac{V}{22,4}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)

PTHH:\(2Fe+6HCl\rightarrow2FeCl_3+3H_2\)

           0,1       0,4            0,1        0,2

\(CM_{HCl}=\dfrac{n_{ct}}{V_{dd}}=\dfrac{0,4}{0,5}\)=0,8(M)

a) nNaCl=0,4.2=0,8(mol)

nAgNO3= 2.0,6=1,2(mol)

PTHH: NaCl + AgNO3 -> NaNO3 + AgCl (kết tủa)

Ta có: nNaCl(p.ứ)/nNaCl(PT) = 0,8/1 < nAgNO3(p.ứ)/nAgNO3(pt)= 1,2/1

=> P.ứ dư AgNO3, có tạo kt AgCl.

nAgCl= nNaNO3=nAgNO3(P.ứ)=nNaCl= 0,8(mol)

=> m(kết tủa)= mAgCl=0,8. 143,5= 114,8(g)

b) Vddsau= 400+600=1000(ml)=1(l)

CMddNaNO3=0,8/1=0,8(M)

CMddAgNO3(dư)= (1,2-0,8.1)/1= 0,4(M)

\(n_{NaOH}=0,2.0,5=0,1\left(mol\right)\\ NaOH+HCl\rightarrow NaCl+H_2O\\ n_{HCl}=n_{NaCl}=n_{NaOH}=0,1\left(mol\right)\\ a,C_{MddHCl}=\dfrac{0,1}{0,05}=2\left(M\right)\\ b,C_{MddNaCl}=\dfrac{0,1}{0,05+0,2}=0,4\left(M\right)\)