Bài 1: (tương tự)

Bài 3: \(n_{khôngkhi}=\dfrac{V}{22,4}=\dfrac{5,6}{22,4}=0,25\left(mol\right)\)

mà \(V_{kk}=5.V_{O2}\)

\(\Rightarrow n_{O2}=\dfrac{n_{kk}}{5}=\dfrac{0,25}{5}=0,05\left(mol\right)\)

\(PT:\) \(2H_2O\underrightarrow{t^0cao}2H_2\uparrow+O_2\uparrow\)

Theo PT ta có: \(n_{H_2O}=2.n_{O_2}=2.0,05=0,1\left(mol\right)\)

\(\Rightarrow m_{H_2O}=n.m=0,1.18=1,8\left(g\right)\)

Bài 2: \(n_{O_2}=\dfrac{V}{22,4}=\dfrac{10,08}{22,4}=0,45\left(mol\right)\)

\(PT:\) \(2KMnO_4\underrightarrow{t^0}K_2MnO_4+MnO_2+O_2\uparrow\)

Theo PT : \(\Rightarrow n_{KMnO_4}=2.n_{O_2}=2.0,45=0,9\left(mol\right)\)

\(\Rightarrow m_{KMnO_4}=n.M=0,9.158=142,2\left(g\right)\)

Bài 1:a) \(n_{CaO}=\dfrac{m}{M}=\dfrac{39,2}{56}=0,7\left(mol\right)\)

\(PT:\) \(CaO+H_2O\rightarrow Ca\left(OH\right)_2\)

b) Theo PT ,ta được:

\(n_{CaO}=n_{Ca\left(OH\right)_2}=0,7\left(mol\right)\)

\(\Rightarrow m_{Ca\left(OH\right)_2}\)_{(lẫn tạp chất)}\(=n.M=0,7.74=51,8\left(g\right)\)

\(\Rightarrow m_{Ca\left(OH\right)_2\left(nguyênchất\right)}=\dfrac{m_{Ca\left(OH\right)_2}.80\%}{100\%}=\dfrac{51,8.80}{100}=41,44\left(g\right)\)

c) Khi thổi CO₂ vào dd vôi tôi để tạo kết tủa nên ta có PT:

\(PT:\) \(CO_2+Ca\left(OH\right)_2\underrightarrow{t^0}CaCO_3+H_2O\)

Theo pt ta có: \(n_{Ca\left(OH\right)_2}=n_{CO_2}=0,7\left(mol\right)\)

\(\Rightarrow V_{CO_2}=n.22,4=0,7.22,4=15,68\left(lít\right)\)

\(n_{FeCl_3}=\dfrac{65.50\%}{100\%.162,5}\approx0,18\left(mol\right)\)

\(PT:\) \(FeCl_3+3NaOH\rightarrow Fe\left(OH\right)_3\downarrow+3NaCl\)

theo PT=> n_NaOH=3.n_FeCl3=3.0,18=0,54(mol)

b) \(V_{ddNaOH}=\dfrac{n}{C_M}=\dfrac{0,54}{2}=0,27\left(lít\right)\)

c)Chất rắn là \(Fe\left(OH\right)_3\)

mà theo pt : \(n_{Fe\left(OH\right)_3}=n_{FeCl_3}=0,18\left(mol\right)\)

=> \(m_{Fe\left(OH\right)_3}=n.M=0,18.107=19,26\left(g\right)\)

@Azue

@Azue

1.It is always cold in water

2. My mother is always busy

3. Do these students somtimes go camping in spring?

4. What do your parents usually do when it's cold?

\(K_2O+H_2SO_4\rightarrow K_2SO_4+H_2O\)

\(Mg\left(OH\right)_2+H_2SO_4\rightarrow MgSO_4+2H_2O\)

\(Al_2O_3+6HCl\rightarrow2AlCl_3+3H_2O\)

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

\(BaO+2HNO_3\rightarrow Ba\left(NO_3\right)_2+H_2O\)