\(n_{SO_2}=\dfrac{6,72}{22,4}=0,3\left(mol\right);n_{KOH}=0,3.2=0,6\left(mol\right)\)

Ta có: \(T=\dfrac{n_{KOH}}{n_{SO_2}}=\dfrac{0,6}{0,3}=2\) ⇒ tạo ra muối K₂SO₃

PTHH: SO₂ + 2KOH → K₂SO₃ + H₂O

Mol:     0,3        0,6           0,3

\(m_{K_2SO_3}=0,3.158=47,4\left(g\right)\)

\(n_{CO_2}=\dfrac{4,48}{22,4}=0,2mol\\ n_{KOH}=0,3.1=0,3mol\\ T=\dfrac{0,3}{0,2}=1,5\)

⇒1<T<2, tạo muối KHCO₃, K₂CO₃

\(n_{K_2CO_3}=a;n_{KHCO_3}=b\\ 2KOH+CO_2\rightarrow K_2CO_3+H_2O\\ KOH+CO_2\rightarrow KHCO_3\\ \Rightarrow\left\{{}\begin{matrix}2a+b=0,3\\a+b=0,2\end{matrix}\right.\\ \Rightarrow a=b=0,1\\ m_{muối}=0,1\left(138+100\right)=23,8g\)

C. 21 gam

c

c

\(n_{SO_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\\ n_{KOH}=1,2\cdot0,3=0,36\left(mol\right)\\ PTHH:SO_2+2KOH\rightarrow K_2SO_3+H_2O\)

Vì \(\dfrac{n_{SO_2}}{1}>\dfrac{n_{KOH}}{2}\) nên SO₂ dư

\(\Rightarrow n_{K_2SO_3}=\dfrac{1}{2}n_{KOH}=0,18\left(mol\right)\\ \Rightarrow m_{K_2SO_3}=0,18\cdot158=28,44\left(g\right)\)

Đáp án C

Ta có: \(\left\{{}\begin{matrix}n_{CO_2}=\dfrac{2,688}{22,4}=0,12\left(mol\right)\\n_{NaOH}=0,2\cdot2=0,4\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\) Tạo muối trung hòa

NaOH dư nên tính theo CO₂

Bảo toàn Cacbon: \(n_{Na_2CO_3}=n_{CO_2}=0,12\left(mol\right)\) \(\Rightarrow m_{Na_2CO_3}=0,12\cdot106=12,72\left(g\right)\)

Ta có: \(n_{CO_2}=\dfrac{2,688}{22,4}=0,12\left(mol\right)\)

\(n_{NaOH}=0,2.2=0,4\left(mol\right)\)

Xét tỉ lệ: \(\dfrac{n_{NaOH}}{n_{CO_2}}=3,33\) 

⇒ Pư tạo muối trung hòa Na₂CO₃.

PT: \(CO_2+2NaOH\rightarrow Na_2CO_3+H_2O\)

____0,12______________0,12 (mol)

\(\Rightarrow m_{Na_2CO_3}=0,12.106=12,72\left(g\right)\)

Bạn tham khảo nhé!

Đáp án là D. 41,7 gam

a)

Gọi $n_{CO_2} =a (mol) ; n_{SO_2} =b (mol)$

\(\dfrac{44a+64b}{a+b}=32.1,6875=54\left(1\right)\)

$2KOH + CO_2 \to K_2CO_3 + H_2O$
$2KOH + SO_2 \to K_2SO_3 + H_2O$

$m_{muối} = 138a + 158b = 29,6(2)$

Từ (1)(2) suy ra a = b = 0,1

$m_X = 0,1.44 + 0,1.64 = 10,8(gam)$

b)

$\%V_{CO_2} = \%V_{SO_2} = \dfrac{0,1}{0,1 + 0,1}.100\% = 50\%$

\(\left\{{}\begin{matrix}n_{SO_2}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\\n_{KOH}=1.0,2=0,2\left(mol\right)\end{matrix}\right.\)

Xét tỉ lệ: \(\dfrac{n_{KOH}}{n_{SO_2}}=\dfrac{0,2}{0,3}=0,67\) => Tạo muối KHSO₃

PTHH: KOH + SO₂ --> KHSO₃

             0,2------------->0,2

=> m_KHSO3 = 0,2.120 = 24 (g)