\(n_{H_2}=\dfrac{22,4}{22,4}=1\left(mol\right)\\ C_{M_{ddHCl}}=\dfrac{1}{0,5}=2\left(M\right)\)

Chọn C.

C

Sục 22,4 lít khí hiđro clorua (đktc) vào nước thu được 500 ml dung dịch axit clohiđric có nồng độ là a mol/L. Giá trị của a là:

A. 1

B. 1,5

C. 2

D. 2,5.

\(n_{HCl}=1\left(mol\right)\Rightarrow CM_{HCl}=\dfrac{1}{0,5}=2M\)

\(n_{HCl}=\dfrac{3,36}{22,4}=0,15\left(mol\right);n_{AgNO_3}=\dfrac{100.1,1.8\%}{170}=\dfrac{22}{425}\left(mol\right)\)

\(AgNO_3+HCl\rightarrow AgCl+HNO_3\)

Lập tỉ lệ: \(\dfrac{22}{425}< \dfrac{0,15}{1}\Rightarrow\)Sau phản ứng HCl dư

\(n_{HNO_3}=n_{AgNO_3}=\dfrac{22}{425}\left(mol\right)\\ m_{ddsaupu}=0,15.36,5+100.1,1-\dfrac{22}{425}.143,5=108,05\left(g\right)\)

\(C\%_{HNO_3}=\dfrac{\dfrac{22}{425}.63}{108,5}.100=3,02\%\)

Bài 10:

- Giả sử có 100 gam dd H₂SO₄ 98%

\(m_{H_2SO_4}=\dfrac{100.98}{100}=98\left(g\right)\) => \(n_{H_2SO_4}=\dfrac{98}{98}=1\left(mol\right)\)

\(V_{dd.H_2SO_4.98\%}=\dfrac{100}{1,84}=\dfrac{1250}{23}\left(ml\right)=\dfrac{5}{92}\left(l\right)\)

\(C_{M\left(dd.H_2SO_4.98\%\right)}=\dfrac{1}{\dfrac{5}{92}}=18,4M\)

\(n_{H_2SO_4}=18,4.0,05=0,92\left(mol\right)\)

=> \(m_{H_2SO_4}=0,92.98=90,16\left(g\right)\)

=> \(m_{dd.H_2SO_4.10\%}=\dfrac{90,16.100}{10}=901,6\left(g\right)\)

Bài 11:

a) Do dd sau pư có 3 chát tan với nồng độ % bằng nhau

=> \(m_{Al_2\left(SO_4\right)_3}=m_{ZnSO_4}=m_{H_2SO_4\left(dư\right)}\)

Gọi số mol Al, Zn là a, b (mol)

PTHH: 2Al + 3H₂SO₄ --> Al₂(SO₄)₃ + 3H₂

             a----->1,5a------->0,5a----->1,5a

            Zn + H₂SO₄ --> ZnSO₄ + H₂

             b----->b--------->b----->b

=> \(\left\{{}\begin{matrix}m_{Al_2\left(SO_4\right)_3}=342.0,5a=171a\left(g\right)\\m_{ZnSO_4}=161b\left(g\right)\end{matrix}\right.\)

=> 171a = 161b 

=> \(\dfrac{a}{b}=\dfrac{161}{171}\) (1)

Có: \(\dfrac{m_{Al}}{m_{Zn}}=\dfrac{27.n_{Al}}{65.n_{Zn}}=\dfrac{27}{65}.\dfrac{161}{171}=\dfrac{483}{1235}\)

b) \(n_{H_2}=1,5a+b=\dfrac{11,2}{22,4}=0,5\left(mol\right)\) (2)

(1)(2) => \(\left\{{}\begin{matrix}a=\dfrac{161}{825}\left(mol\right)\\b=\dfrac{57}{275}\left(mol\right)\end{matrix}\right.\)

=> \(x=\dfrac{161}{825}.27+\dfrac{57}{275}.65=\dfrac{5154}{275}\left(g\right)\)

\(m_{H_2SO_4\left(dư\right)}=m_{Al_2\left(SO_4\right)_3}=342.0,5\dfrac{161}{825}=\dfrac{9177}{275}\left(g\right)\)

=> \(m_{H_2SO_4\left(bđ\right)}=98\left(1,5a+b\right)+\dfrac{9177}{275}=\dfrac{22652}{275}\left(g\right)\)

=> \(y=\dfrac{\dfrac{22652}{275}.100}{10}=\dfrac{45304}{55}\left(g\right)\)