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2.a)\(n_{Zn}=\frac{13}{65}=0,2\left(mol\right)\)
PTHH: Zn + 2HCl -------> ZnCl2 + H2
Theo PT : nHCl =2nZn =0,4(mol)
=> \(m_{ddHCl}=\frac{0,4.36,5}{10\%}=146\left(g\right)\)
b)dd sau phản ứng : ZnCl2
nH2 =nZn =0,2(mol)
mddsau phản ứng = 146+ 13- 0,2.2 = 158,6(g)
=>\(C\%_{ZnCl_2}=\frac{0,2.136}{158,6}.100=17,15\%\)
4. \(n_{H_2SO_4}=0,2.1=0,2\left(mol\right)\)
PTHH: H2SO4 + 2NaOH --------> Na2SO4 + 2H2O
Theo PT : n NaOH = 2n H2SO4 =0,4 (mol)
=> \(m_{ddNaOH}=\frac{0,4.40}{20\%}=80\left(g\right)\)
1/ \(n_{K_2SO_3}=\frac{15,8}{158}=0,1\left(mol\right)\)
PTHH: K2SO3 + 2HCl ---------> 2KCl + SO2 + H2O
a) Theo PT : nHCl =2nK2SO3 = 0,2(mol)
=>\(m_{ddHCl}=\frac{0,2.36,5}{7,3\%}=100\left(g\right)\)
b) Theo PT : nSO2 =nK2SO3 = 0,1(mol)
=> \(V_{SO_2}=0,1.22,4=2,24\left(l\right)\)
c) dd sau phản ứng : KCl
Theo Pt: nKCl =2nK2SO3 = 0,2(mol)
mddsau phản ứng = 100+ 15,8 - 0,1.64 = 109,4 (g)
=> \(C\%_{KCl}=\frac{0,2.74,5}{109,4}.100=13,62\%\)
$NaOH + HCl \to NaCl + H_2O$
Theo PTHH :
$n_{NaOH} = n_{HCl} = 0,6(mol)$
$m_{dd\ NaOH} = \dfrac{0,6.40}{30\% } = 80(gam)$
$n_{NaCl} = n_{HCl} = 0,6(mol)$
$m_{NaCl} = 0,6.58,5 = 35,1(gam)$
600ml = 0,6l
Số mol của dung dịch axit clohidric
CMHCl = \(\dfrac{n}{V}\Rightarrow n=C_M.V=1.0,6=0,6\left(mol\right)\)
Pt : HCl + NaOH → NaCl + H2O\(|\)
1 1 1 1
0,6 0,6 0,6
Số mol của natri hidroxit
nNaOH = \(\dfrac{0,6.1}{1}=0,6\left(mol\right)\)
Khối lượng của natri hidroxit
mNaOH = nNaOH . MNaOH
= 0,6 . 40
= 24 (g)
Khối lượng của dung dịch natri hidroxit cần dùng
C0/0NaOH = \(\dfrac{m_{ct}.100}{m_{dd}}\Rightarrow m_{dd}=\dfrac{m_{ct}.100}{C}=\dfrac{24.100}{30}=80\left(g\right)\)
Số mol của muối natri clorua
nNaCl = \(\dfrac{0,6.1}{1}=0,6\left(mol\right)\)
Khối lượng của muối natri clorua
mNaCl = nNaCl . MNaCl
= 0,6 . 58,5
= 35,1 (g)
Chúc bạn học tốt
PTHH: \(K_2SO_3+2HCl\rightarrow2KCl+H_2O+SO_2\uparrow\)
a+b+c) Ta có: \(n_{SO_2}=\dfrac{5,6}{22,4}=0,25\left(mol\right)\)
\(\Rightarrow\left\{{}\begin{matrix}n_{KCl}=0,5\left(mol\right)=n_{HCl}\\n_{K_2SO_3}=0,25\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}m_{K_2SO_3}=0,25\cdot158=39,5\left(g\right)=a\\m_{KCl}=0,5\cdot74,5=37,25\left(g\right)\\m_{ddHCl}=\dfrac{0,5\cdot36,5}{10,95\%}\approx166,67\left(g\right)\end{matrix}\right.\)
Mặt khác: \(m_{SO_2}=0,25\cdot64=16\left(g\right)\)
\(\Rightarrow m_{dd}=m_{K_2SO_3}+m_{ddHCl}-m_{SO_2}=190,17\left(g\right)\) \(\Rightarrow C\%_{KCl}=\dfrac{37,25}{190,17}\cdot100\%\approx19,59\%\)
d) PTHH: \(NaOH+HCl\rightarrow NaCl+H_2O\)
Theo PTHH: \(n_{NaOH}=n_{HCl}=0,5\left(mol\right)\) \(\Rightarrow V_{NaOH}=\dfrac{0,5}{0,5}=1\left(l\right)\)
a,\(n_{CO_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)
PTHH: CaCO3 + 2HCl → CaCl2 + CO2 + H2O
Mol: 0,1 0,2 0,1
\(m_{CaCO_3}=0,1.100=10\left(g\right)\)
b,\(C\%_{ddHCl}=\dfrac{0,2.36,5.100\%}{150}=4,87\%\)
c,mdd sau pứ= 10+150-0,1.44 = 151,2 (g)
\(C\%_{ddCaCl_2}=\dfrac{0,1.111.100\%}{151,2}=7,34\%\)
Tiếp bài của creeper nhé:
c. Ta có: \(n_{ZnO}=\dfrac{4,86}{81}=0,06\left(mol\right)\)
Theo PT(1): \(n_{HCl}=2.n_{ZnO}=2.0,06=0,12\left(mol\right)\)
Theo PT(2): \(n_{HCl}=2.n_{Zn}=2.0,1=0,2\left(mol\right)\)
=> \(n_{HCl}=0,12+0,2=0,32\left(mol\right)\)
=> \(m_{HCl}=0,32.36,5=11,68\left(g\right)\)
Ta có: \(C_{\%_{HCl}}=\dfrac{11,68}{m_{dd_{HCl}}}.100\%=12\%\)
=> \(m_{dd_{HCl}}=\dfrac{292}{3}\left(g\right)\)
Theo đề, ta có:
\(D=\dfrac{\dfrac{292}{3}}{V_{dd_{HCl}}}=1,2\)(g/ml)
=> \(V_{dd_{HCl}}=81,1\left(ml\right)\)
200ml = 0,2l
\(n_{Zn}=\dfrac{19,5}{65}=0,3\left(mol\right)\)
Pt : \(Zn+2HCl\rightarrow ZnCl_2+H_2|\)
1 2 1 1
0,3 0,6 0,3 0,3
a) \(n_{ZnCl2}=\dfrac{0,3.1}{1}=0,3\left(mol\right)\)
\(C_{M_{ZnCl2}}=\dfrac{0,3}{0,2}=1,5\left(M\right)\)
b) \(n_{H2}=\dfrac{0,3.1}{1}=0,3\left(mol\right)\)
\(V_{H2\left(dktc\right)}=0,3.22,4=6,72\left(l\right)\)
c) Pt : \(NaOH+HCl\rightarrow NaCl+H_2O|\)
1 1 1 1
0,6 0,6
\(n_{NaOH}=\dfrac{0,6.1}{1}=0,6\left(mol\right)\)
\(m_{NaOH}=0,6.40=24\left(g\right)\)
\(m_{ddNaOH}=\dfrac{24.100}{20}=120\left(g\right)\)
Chúc bạn học tốt
*Sửa đề: "13,44 lít H2" và "24,9 gam hh 2 kim loại"
PTHH: \(2Al+6HCl\rightarrow2AlCl_3+3H_2\uparrow\)
a_____3a_____________\(\dfrac{3}{2}\)a (mol)
\(Zn+2HCl\rightarrow ZnCl_2+H_2\uparrow\)
b_____2b_____________b (mol)
Ta lập HPT: \(\left\{{}\begin{matrix}27a+65b=24,9\\\dfrac{3}{2}a+b=\dfrac{13,44}{22,4}=0,6\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}a=0,2\\b=0,3\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}n_{Al}=0,2\left(mol\right)\\n_{Zn}=0,3\left(mol\right)\\n_{HCl}=1,2\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}m_{Al}=0,2\cdot27=5,4\left(g\right)\\m_{Zn}=19,5\left(g\right)\\m_{ddHCl}=\dfrac{1,2\cdot36,5}{7,3\%}=600\left(g\right)\end{matrix}\right.\)
a)
\(n_{H_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)
PTHH: Mg + 2HCl --> MgCl2 + H2
_____0,1<---0,2<-------0,1<---0,1
=> mHCl = 0,2.36,5 = 7,3 (g)
=> \(m_{ddHCl}=\dfrac{7,3.100}{7,3}=100\left(g\right)\)
mdd sau pư = 0,1.24 + 100 - 0,1.2 = 102,2 (g)
\(C\%\left(MgCl_2\right)=\dfrac{0,1.95}{102,2}.100\%=9,2955\%\)
b)
CTHH: AaOb
PTHH: \(A_aO_b+2bHCl->aACl_{\dfrac{2b}{a}}+bH_2O\)
____________0,2------->\(\dfrac{0,1a}{b}\)
=> \(\dfrac{0,1a}{b}\left(M_A+35,5.\dfrac{2b}{a}\right)=13,5\)
=> \(M_A=\dfrac{64b}{a}=\dfrac{2b}{a}.32\)
Nếu \(\dfrac{2b}{a}=1\) => MA = 32 (L)
Nếu \(\dfrac{2b}{a}=2\) => MA = 64(Cu)
1) a, n\(K_2SO_4\)= \(\frac{15,8}{158}=0,1mol\)
pt : K2SO4 + 2HCl → 2KCl + H2O + SO2
(mol) 0,1mol → 0,2mol → 0,2mol → 0,1mol
mHCl = 0,2 . 36,5 = 7,3 g
b, VSO2 = 0,1 . 22,4 = 2,24 l
c, mdd = \(\frac{7,3.100}{7,3}=100g\)
C% = \(\frac{0,2.74,5.100}{100}=14,9\%\)
Bài 2: PTHH: \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
a) Ta có: \(n_{Zn}=\frac{13}{65}=0,2\left(mol\right)\) \(\Rightarrow n_{HCl}=0,4mol\)
\(\Rightarrow m_{HCl}=0,4\cdot36,5=14,6\left(g\right)\) \(\Rightarrow m_{ddHCl}=\frac{14,6}{10\%}=146\left(g\right)\)
b) Theo PTHH: \(n_{Zn}=n_{ZnCl_2}=0,2mol=n_{H_2}\)
\(\Rightarrow\left\{{}\begin{matrix}m_{ZnCl_2}=0,2\cdot136=27,2\left(g\right)\\m_{H_2}=0,2\cdot2=0,4\left(g\right)\end{matrix}\right.\)
\(\Rightarrow m_{dd}=m_{Zn}+m_{ddHCl}-m_{H_2}=13+146-0,4=158,6\left(g\right)\)
\(\Rightarrow C\%_{ZnCl_2}=\frac{27,2}{158,6}\cdot100\approx17,15\%\)