mKOH=28(g)

nKOH=0.5(mol)

PTHH:2KOH+H2SO4->K2SO4+2H2O

a)Theo pthh:nH2SO4=1/2 nKOH->nH2SO4=0.25(mol)

mH2SO4=0.25*98=24.5(g)

C%ddH2SO4=24.5/100*100=24.5%

theo pthh:nK2SO4=nH2SO4->nK2SO4=0.25(mol)

mK2SO4=0.25*(39*2+96)=43.5(g)

c)mdd sau phản ứng:200+100=300(g)

d) C% muối=43.5:300*100=14.5%

mH2SO4=200.9,8%=19,6(g) -> nH2SO4=19,6/98=0,2(mol)

mKOH=200.5,6%=11,2(g) -> nKOH=11,2/56=0,2(mol)

PTHH: 2 KOH + H2SO4 -> K2SO4 + 2 H2O

Ta có: 0,2/2 < 0,2/1

=> H2SO4 dư, KOH hết, tính theo nKOH 

=> Chất có trong dd thu được sau p.ứ: K2SO4 và H2SO4(dư)

nH2SO4(p.ứ)=nK2SO4=1/2. nKOH=1/2. 0,2=0,1(mol)

nH2SO4(dư)=0,2-0,1=0,1(mol) => mH2SO4(dư)=0,1.98=9,8(g)

mK2SO4=174. 0,1=17,4(g)

mddsau= mddH2SO4 + mddKOH= 200+200=400(g)

=>C%ddH2SO4(dư)= (9,8/400).100=2,45%

C%ddK2SO4=(17,4/400).100=4,35%

\(m_{H_2SO_4}=19,6\left(g\right)\Rightarrow n_{H_2SO_4}=0,2\left(mol\right)\)

\(m_{KOH}=11,2\left(g\right)\Rightarrow n_{KOH}=0,2\left(mol\right)\)

PTHH: \(H_2SO_4+2KOH\rightarrow K_2SO_4+2H_2O\)

\(\Rightarrow H_2SO_4\) dư.

\(\Rightarrow n_{H_2SO_4dư}=0,3\left(mol\right);n_{K_2SO_4}=0,1\left(mol\right)\)

\(\Rightarrow C\%_{H_2SO_4dư}=\dfrac{0,3.98}{400}.100\%=7,35\%\)

\(C\%_{K_2SO_4}=\dfrac{0,1.174}{400}.100\%=4,35\%\)

Ta có: \(C_{\%_{H_2SO_4}}=\dfrac{m_{H_2SO_4}}{200}.100\%=14,7\%\)

=> \(m_{H_2SO_4}=29,4\left(g\right)\)

=> \(n_{H_2SO_4}=\dfrac{29,4}{98}=0,3\left(mol\right)\)

a. PTHH: 2KOH + H₂SO₄ ---> K₂SO₄ + 2H₂O

Theo PT: \(n_{KOH}=2.n_{H_2SO_4}=2.0,3=0,6\left(mol\right)\)

=> \(m_{KOH}=0,6.56=33,6\left(g\right)\)

Ta có: \(C_{\%_{KOH}}=\dfrac{33,6}{m_{dd_{KOH}}}.100\%=5,6\%\)

=> \(m_{dd_{KOH}}=600\left(g\right)\)

Theo đề, ta có: 

\(D=\dfrac{600}{V_{dd_{KOH}}}=10,45\)(g/ml)

=> \(V_{dd_{KOH}}=57,42\left(ml\right)\)

b. Ta có: \(m_{dd_{K_2SO_4}}=200+33,6=233,6\left(g\right)\)

Theo PT: \(n_{K_2SO_4}=n_{H_2SO_4}=0,3\left(mol\right)\)

=> \(m_{K_2SO_4}=0,3.174=52,2\left(g\right)\)

=> \(C_{\%_{K_2SO_4}}=\dfrac{52,2}{233,6}.100\%=22,35\%\)

hyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyydjyh

hyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyydjyh