\(a.2Na+2H_2O\rightarrow2NaOH+H_2\\ b.n_{Na}=\dfrac{9,2}{23}=0,4\left(mol\right)\\ n_{H_2}=\dfrac{1}{2}n_{Na}=0,2\left(mol\right)\\ \Rightarrow V_{H_2}=0,2.22,4=4,48\left(l\right)\\ n_{NaOH}=n_{Na}=0,4\left(mol\right)\\ \Rightarrow m_{NaOH}=0,4.40=16\left(g\right)\\ c.H_2+CuO-^{t^o}\rightarrow Cu+H_2O\\ n_{CuO}=\dfrac{12}{80}=0,15\left(mol\right)\\ LTL:\dfrac{0,2}{1}>\dfrac{0,15}{1}\Rightarrow H_2dưsauphảnứng\\ n_{H_2\left(pứ\right)}=n_{CuO}=0,15\left(mol\right)\\ \Rightarrow n_{H_2\left(dư\right)}=0,2-0,15=0,05\left(mol\right)\\ \Rightarrow m_{H_2\left(Dư\right)}=0,05.2=0,1\left(g\right)\)

a)PTHH: Na+H2O---> NaOH+H2
b)nNa= \(\dfrac{m}{M}=\dfrac{2,3}{23}=0,1\left(mol\right)\)

=>n_Na=n_H2=0,1 (mol)

=>V_H2=n.22,4=0,1.22,4=2,24(l)

c)n_Na=n_H2O=n_NaOH=0,1 (mol)

=>m_H2O=0,1.18=1,8(g)

d)m_NaOH=0,1.(23+16+1)=4(g)

Học tốt !

a, \(2Na+2H_2O\rightarrow2NaOH+H_2\)

b, \(n_{Na}=\dfrac{2,3}{23}=0,1\left(mol\right)\)

Theo PT: \(n_{H_2}=\dfrac{1}{2}n_{Na}=0,05\left(mol\right)\Rightarrow V_{H_2}=0,05.22,4=1,12\left(l\right)\)

c, \(n_{H_2O}=n_{Na}=0,1\left(mol\right)\Rightarrow m_{H_2O}=0,1.18=1,8\left(g\right)\)

d, \(n_{NaOH}=n_{Na}=0,1\left(mol\right)\Rightarrow m_{NaOH}=0,1.40=4\left(g\right)\)

\(n_K=\dfrac{3,9}{39}=0,1mol\)

\(2K+2H_2O\rightarrow2KOH+H_2\)

0,1                        0,1      0,05 ( mol )

\(m_{KOH}=0,1.56=5,6g\)

\(V_{H_2}=0,05.22,4=1,12l\)

2K+2H2O->2KOH+H2

0,1-----------------0,1---0,05

n K=0,1 mol

=>m KOH=0,1.56=5,6g

VH2=0,05.22,4=1,12l

⇒ Chọn D.

\(n_{Fe}=\dfrac{2.8}{56}=0.05\left(mol\right)\)

\(Fe+2HCl\rightarrow FeCl_2+H_2\)

\(0.05................................0.05\)

\(V_{H_2}=0.05\cdot22.4=1.12\left(l\right)\)

\(n_{CuO}=\dfrac{6}{80}=0.075\left(mol\right)\)

\(CuO+H_2\underrightarrow{^{^{t^0}}}Cu+H_2O\)

\(1............1\)

\(0.075......0.05\)

Chất khử : H₂ . Chất OXH : CuO 

\(LTL:\dfrac{0.075}{1}>\dfrac{0.05}{1}\Rightarrow CuOdư\)

\(m_{CuO\left(dư\right)}=\left(0.075-0.05\right)\cdot64=1.6\left(g\right)\)

a) Zn + 2HCl --> ZnCl₂ + H₂

b) \(n_{Zn}=\dfrac{13}{65}=0,2\left(mol\right)\)

PTHH: Zn + 2HCl --> ZnCl₂ + H₂

          0,2-->0,4----->0,2--->0,2

=> V_H2 = 0,2.22,4 = 4,48 (l)

c) 

PTHH: CuO + H₂ --t^o--> Cu + H₂O

Xét tỉ lệ: \(\dfrac{0,3}{1}>\dfrac{0,2}{1}\) => CuO dư, H₂ hết

PTHH: CuO + H₂ --t^o--> Cu + H₂O

                        0,2----->0,2

=> m_Cu = 0,2.64 = 12,8 (g)

a)\(PTHH:2Na+2H_2O\xrightarrow[]{}2NaOH+H_2\)

b)\(n_{Na}=\dfrac{4,6}{23}=0,2\left(m\right)\)

\(PTHH:2Na+2H_2O\xrightarrow[]{}2NaOH+H_2\)

tỉ lệ        :2          2             2               1(mol)

số mol   :0,2       0,2          0,2             0,1

\(V_{H_2}=0,1.22,4=2,24\left(l\right)\)

c)\(m_{NaOH}=0,2.40=8\left(g\right)\)

\(2Na+2H_2O\rightarrow2NaOH+H_2\\ n_{Na}=\dfrac{4,6}{23}=0,2\left(mol\right)\\ n_{H_2O}=\dfrac{1,8}{18}=0,1\left(mol\right)\\ LTL:\dfrac{0,2}{2}>\dfrac{0,1}{2}\\ \Rightarrow Nadư\\ n_{Na\left(pứ\right)}=n_{H_2O}=0,1\left(mol\right)\\ n_{Na\left(dư\right)}=0,2-0,1=0,1\left(mol\right)\\ \Rightarrow m_{Na}=0,1.23=2,3\left(g\right)\\ n_{H_2}=\dfrac{1}{2}n_{H_2O}=0,05\left(mol\right)\\ \Rightarrow V_{H_2}=0,05.22,4=1,12\left(l\right)\)

\(m_{NaOH}=200.10\%=20\left(g\right)\Rightarrow n_{NaOH}=\dfrac{20}{40}=0,5\left(mol\right)\)

PTHH: 2Na + 2H₂O → 2NaOH + H₂

Mol:     0,5                           0,5             0,5

\(m_{Na}=0,5.23=11,5\left(g\right)\)

\(V_{H_2}=0,25.22,4=5,6\left(l\right)\)

làm gì có a g đ

a. \(Fe+2HCl\rightarrow FeCl_2+H_2\)

b. \(n_{Fe}=\dfrac{m_{Fe}}{M_{Fe}}=\dfrac{28}{56}=0,5\left(mol\right)\)

\(Fe+2HCl\rightarrow FeCl_2+H_2\)

0,5-------1---------0,5-----0,5

Theo PTHH: \(\Rightarrow n_{H_2}=n_{Fe}=0,5\left(mol\right)\)

\(V_{H_2}=n_{H_2}.22,4=0,5.22,4=11,2\left(l\right)\)

c. \(H_2+CuO\rightarrow Cu+H_2O\)

  0,5-------0,5-----0,5----0,5

\(\Rightarrow m_{Cu}=n_{Cu}.M_{Cu}=0,5.64=32\left(g\right)\)