a. \(n_{HCl}=\frac{44,8}{22,4}=2mol\)

\(\rightarrow m_{HCl}=2.36,5=73g\)

\(\rightarrow C\%_{HCl}=\frac{73.100}{73+327}=18,25\%\)

b. \(n_{CaCO_3}=\frac{50}{100}=0,5mol\)

\(n_{HCl}=\frac{250.18,25\%}{36,25}=1,25mol\)

PTHH: \(CaCO_3+2HCl\rightarrow CaCl_2+CO_2+H_2O\)

Từ phương trình \(n_{CaCl_2}=n_{CO_2}=0,5mol\)

\(n_{HCl\text{pứ}}=0,5.2=1mol\)

\(\rightarrow n_{HCl\text{dư}}=1,25-1=0,25mol\)

\(n_{ddsaupu}=50+250-0,5.44=278g\)

\(\rightarrow C\%_{CaCl_2}=\frac{0,5.111.100}{278}=19,96\%\)

\(\rightarrow C\%_{HCl}=\frac{0,25.36,5.100}{278}=3,28\%\)

Bảo toàn khối lượng

\(m_{O_2}=m_{Oxit}-m_{KL}=48,84-34,44=14,4g\)

\(\rightarrow n_{O_2}=\frac{14,4}{32}=0,45mol\)

BTNT (O) \(n_{H_2O}=2n_{O_2}=0,9mol\)

\(n_{H_2}=\frac{4,032}{22,4}=0,18mol\)

BTNT (H)  \(n_{HCl}=2n_{H_2O}+2n_{H_2}=2,16mol\)

\(\rightarrow m_{HCl}=2,16.36,5=78,84g\)

\(m_{H_2}=0,18.2=0,36g\) và \(m_{H_2O}=0,9.18=16,2g\)

Bảo toàn khối lượng \(m_A+m_{HCl}=m_{\text{muối}}+m_{H_2O}+m_{H_2}\)

\(\rightarrow m_{\text{muối}}=48,84+78,84-0,36-16,2=111,12g\)

vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv

a. \(Mg+CU\left(NO_3\right)_2\rightarrow Mg\left(NO_3\right)_2+Cu\downarrow\)

b. \(n_{Cu\left(\text{pứ}\right)}=a\left(mol\right)\)

\(\rightarrow m_{Mg\left(\tan\right)}=24a\) và \(m_{Cu\left(bám\right)}=64a\)

\(\rightarrow40-m_{Mg\left(\tan\right)}+m_{Cu\left(bám\right)}=48\)

\(\rightarrow40-24a+64a=48\)

\(\rightarrow a=0,2mol\)

c. \(m_{Cu}=0,2.64=12,8g\)

PRESERVING THE PAST

Life has changed a lot over the past 50 years, and there are many good pastimes which seem to be dying out. Work in groups and search for a past tradition or pastime which you highly appreciate give reasons why you it work out a plan to help preserve it. Then make a poster presenting your ideas and share it with your class

many other traditions, the spirit of patriotism is a feature of our country's long-standing culture, it is expressed from the past to the present and goes into every action and thought of each person. Since ancient times, the spirit of patriotism is most clearly disclosed in the mirror heroes Hai Ba Trung, Ba Trieu, Tran Hung Dao and so on ... But it is in times of war. Also now - peacetime - the modernization period with machines and tools being increasingly useful and pracal. The society is more and more advanced, everything has changed a lot, only the patriotism of each individual is still not blurred. In the life of thoughts, jobs to help develop the country's economy are partly patrio.

vì sản phẩm có C và H2o

0,3mol chứ nhỉ?

a. \(2Al+6HCl\rightarrow2AlCl_3+3H_2\uparrow\left(1\right)\)

\(FeO+2HCl\rightarrow FeCl_2+H_2O\left(2\right)\)

\(Fe_2O_3+6HCl\rightarrow2FeCl_3+3H_2O\left(3\right)\)

b. Theo phương trình \(n_{Al}=\frac{2}{3}n_{H_2}=0,2mol\) và \(n_{HCl\left(1\right)}=0,6mol\)

\(\rightarrow m_{FeO}+m_{Fe_2O_3}=35,8-0,2.27=30,4g\)

Đặt \(\hept{\begin{cases}n_{FeO}=x\\n_{Fe_2O_3}=y\end{cases}}\)

\(\rightarrow72x+160y=30,4\left(1\right)\)

Theo phương trình \(2x+6y=n_{HCl\left(2+3\right)}=1,6.1-0,6=1\left(2\right)\)

Từ (1) và (2) suy ra x = 0,2 và y = 0,1

\(\rightarrow m_{FeO}=0,2.72=14,4g\) và \(m_{Fe_2O_3}=0,1.160=16g\)

\(\rightarrow\%m_{FeO}=\frac{14,4}{35,8}.100\%\approx40,22\%\)

\(\rightarrow\%m_{Fe_2O_3}=\frac{16}{35,8}.100\%\approx44,69\%\)

c. Theo phương trình \(n_{AlCl_3}=0,2mol\) và \(n_{FeCl_2}=0,2mol\) và \(n_{FeCl_3}=0,2mol\)

\(\rightarrow m_{\text{muối}}=0,2.133,5+0,2.127+0,2.162,5=84,6g\)