Zn+2HCl->Zncl2+H2

0,4----0,8----0,4----0,4

n Zn=0,4 mol

VH2=0,4.22,4=8,96l

m ZnCl2=0,4.136=54,4g

2H2+O2-to>2H2O

0,4------0,2----0,4

n O2=0,2 mol

=>pứ hết 

=>m H2O=0,4.18=7,2g

a.b.\(n_{Zn}=\dfrac{26}{65}=0,4mol\)

\(Zn+2HCl\rightarrow ZnCl_2+H_2\)

0,4                      0,4       0,4       ( mol )

\(m_{ZnCl_2}=0,4.136=54,4g\)

\(V_{H_2}=0,4.22,4=8,96l\)

c.\(n_{O_2}=\dfrac{4,48}{22,4}=0,2mol\)

\(2H_2+O_2\rightarrow\left(t^o\right)2H_2O\)

0,4   = 0,2                       ( mol )

0,4        0,2            0,4        ( mol )

\(m_{H_2O}=0,4.18=7,2g\)

\(n_{Mg}=\dfrac{4,8}{24}=0,2\left(mol\right)\\ pthh:CH_4+2O_2\underrightarrow{t^o}CO_2+2H_2O\)
               0,2    0,4                  0,4 
\(V_{O_2}=0,4.22,4=8,96\left(l\right)\\ m_{H_2O}=0,4.18=7,2\left(g\right)\)

Gọi x, y là số mol của C và S, ta có:

\(C+O_2\rightarrow CO_2\)

x       x            x

\(S+O_2\rightarrow SO_2\)

y       y          y

\(\Rightarrow\left\{{}\begin{matrix}x+y=\dfrac{4,48}{22,4}=0,2\\12x+32y=4,4\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}x=0,1\\y=0,1\end{matrix}\right.mol\)

\(\Rightarrow m_{hh}=0,1.44+0,1.64=10,8g\)

a) 2H₂ + O₂ --t^o--> 2H₂O

b) \(n_{H_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)

PTHH: 2H₂ + O₂ --t^o--> 2H₂O

            0,1-->0,05------>0,1

=> m_H2O = 0,1.18 = 1,8 (g)

c) \(n_{O_2\left(bđ\right)}=\dfrac{1,344}{22,4}=0,06\left(mol\right)>n_{O_2\left(pư\right)}=0,05\left(mol\right)\)

=> O₂ dư

n_O2(dư) = 0,06 - 0,05 = 0,01 (mol)

V_O2(dư) = 0,01.22,4 = 0,224 (l)

\(n_{O_2}=\dfrac{8}{32}=0.25\left(mol\right)\)

\(CH_4+2O_2\underrightarrow{t^0}CO_2+2H_2O\)

\(0.125....0.25....0.125\)

\(m_{CH_4}=0.125\cdot16=2\left(g\right)\)

\(V_{CO_2}=0.125\cdot22.4=2.8\left(l\right)\)

\(Ca\left(OH\right)_2+CO_2\rightarrow CaCO_3+H_2O\)

\(............0.125.....0.125\)

\(m_{CaCO_3}=0.125\cdot100=12.5\left(g\right)\)

a.\(n_{CH_4}=\dfrac{V_{CH_4}}{22,4}=\dfrac{6,72}{22,4}=0,3mol\)

\(CH_4+2O_2\rightarrow\left(t^o\right)CO_2+2H_2O\)

0,3       0,6                                          ( mol )

\(V_{O_2}=n_{O_2}.22,4=0,6.22,4=13,44l\)

b.

\(n_P=\dfrac{m_P}{M_P}=\dfrac{3,1}{31}=0,1mol\)

\(4P+5O_2\rightarrow\left(t^o\right)2P_2O_5\)

0,1                         0,05    ( mol )

\(m_{P_2O_5}=n_{P_2O_5}.M_{P_2O_5}=0,05.142=7,1g\)

a, \(2Mg+O_2\underrightarrow{^{t^o}}2MgO\)

\(n_{MgO}=\dfrac{2}{40}=0,05\left(mol\right)\)

\(n_{O_2}=\dfrac{1}{2}n_{MgO}=0,025\left(mol\right)\Rightarrow V_{O_2}=0,025.22,4=0,56\left(l\right)\)

b, Có lẽ đề cho oxi tác dụng với hidro chứ không phải oxit bạn nhỉ?

\(n_{H_2}=\dfrac{3,36}{22,4}=0,15\left(mol\right)\)

PT: \(2H_2+O_2\underrightarrow{^{t^o}}2H_2O\)

Xét tỉ lệ: \(\dfrac{0,15}{2}>\dfrac{0,025}{1}\), ta được H₂ dư.

THeo PT: \(n_{H_2O}=2n_{O_2}=0,05\left(mol\right)\Rightarrow m_{H_2O}=0,05.18=0,9\left(g\right)\)

\(n_{CH_4}=\dfrac{3,2}{16}=0,2\left(mol\right)\)

PTHH: CH₄ + 2O₂ --t^o--> CO₂ + 2H₂O

            0,2--->0,4--------->0,2

\(\rightarrow\left\{{}\begin{matrix}V_{O_2}=0,4.22,4=8,96\left(l\right)\\m_{CO_2}=0,2.44=8,8\left(g\right)\end{matrix}\right.\)

a) PƯHH: \(CH_4+2O_2\xrightarrow[]{t^0}CO_2\uparrow+2H_2O\)

b) Theo định luật bảo toàn khối lượng, ta có: 

\(m_{CH_4}+m_{O_2}=m_{CO_2}+m_{H_2O}\)

\(\Rightarrow m_{O_2}=m_{CO_2}+m_{H_2O}-m_{CH_4}=44+36-16=64\) (g)