\(CaHPO_4+NaHSO_4\rightarrow CaSO_4+NaH_2PO_4\)

Bài 1 :

Gọi 

\(n_{Fe} = a(mol) ; n_{Zn} = b(mol)\\ Fe + 2HCl \to FeCl_2 + H_2\\ Zn + 2HCl \to ZnCl_2 + H_2\\ \)

Ta có : 

\(\hept{\begin{cases}n_{H_2}=a+b=\frac{3,36}{22,4}=0,15\left(mol\right)\\m_{muoi}=127a+136b=19,5\left(gam\right)\end{cases}}\)

\(\Rightarrow\hept{\begin{cases}a=0,1\\b=0,05\end{cases}}\)\(\Rightarrow\hept{\begin{cases}m_{Fe}=0,1.56=5,6\left(gam\right)\\m_{Zn}=0,05.65=3,25\left(gam\right)\end{cases}}\)

Bài 2 : 

\(\hept{\begin{cases}n_{BaCO_3}=a\left(mol\right)\\n_{BaSO_3}=b\left(mol\right)\end{cases}}\)

\(BaCO_3 + 2HCl \to BaCl_2 + CO_2 + H_2O\\ BaSO_3 + 2HCl \to BaCl_2 + SO_2 + H_2O\)

Ta có : 

\(\hept{\begin{cases}m_{hh}=197a+217b=20,5\left(gam\right)\\n_{khí}=n_{CO_2}+n_{SO_2}=a+b=\frac{2,24}{22,4}=0,1\left(mol\right)\end{cases}}\)

Suy ra:  a = 0,06 ; b = 0,04

\(\%m_{BaCO_3} = \dfrac{0,06.197}{20,5}.100\% =57,66\%\\ \%m_{BaSO_3} = 100\%- 57,66\%=42,34\%\)

\(n_{FeCl_2}=0,25mol\)

Đặt \(\hept{\begin{cases}x=n_{Fe}\\y=n_{FeO}\\z=n_{FeCO_3}\end{cases}}\)

Có \(\frac{2x+44z}{x+z}=30\rightarrow-28x+14z=0\)

BT Fe \(x+y+z=0,25\)

Có hệ phương trình

\(\hept{\begin{cases}56x+72y+116z=21,6\\x+y+z=0,25\\-28x+14z=0\end{cases}}\)

\(\rightarrow\hept{\begin{cases}x=0,05\\y=0,1\\z=0,1\end{cases}}\)

\(\%m_{Fe}=\frac{0,05.56}{21,6}.100\%=12,9\%\)

\(\%m_{FeO}=\frac{0,1.72}{21,6}.100\%=33,3\%\)

\(\rightarrow\%m_{FeCO_3}=100\%-12,9\%-33,3\%=53,8\%\)

\(Fe + 2HCl \to FeCl_2 + H_2\\ FeO + 2HCl \to FeCl_2 + H_2O\\ FeCO_3 + 2HCl \to FeCl_2 + CO_2 + H_2O\)

\(n_{FeCl_2}=\frac{31,75}{127}=0,25\left(mol\right)\)

\(\hept{\begin{cases}n_{Fe}=a\\n_{FeO}=b\\n_{FeCO_3}=c\end{cases}\Rightarrow\hept{\begin{cases}56a+72b+116b=21,6\\n_{FeCl_2}=a+b+c=0,25\\\frac{2a+44c}{a+c}=7,5.4\end{cases}}}\)

\(\Rightarrow\hept{\begin{cases}a=0,05\\b=0,1\\c=0,1\end{cases}\Rightarrow\%m_{Fe}=\frac{0,05.56}{21,6}.100\%=12,96\%}\)

cái thứ 4 nhé bạn vì 2mFe(OH)₃=m2Fe(OH)₃, 3mH2O =m3H2O mà 2Fe(OH)₃\(\rightarrow\) 3H2O+Fe2O3 nên theo định luật bảo toàn khối lượng ta chọn câu 4

milk ko biết làm

Khối lượng nguyên tử Oxi là: \(\frac{1,9926.10^{-23}.16}{12}=2,6568.10^{-23}g\)

Khối lượng nguyên tử lưu huỳnh là: \(\frac{1,9926.10^{-23}.32}{12}=5,3136.10^{-23}g\)

Khối lượng nguyên tử Magie là: \(\frac{1,9926.10^{-23}.24}{12}=3,9852.10^{-23}g\)

Khối lượng nguyên tử Bari là: \(\frac{1.9926.10^{-23}.137}{12}=2,274885.10^{-23}g\)

Trả lời:

- Hơi nước

- Ô xi

- Nitơ

- Các bo nic

........................

Mk chỉ làm đc vậy thôi, bn k cho mk nha..

Trả lời :

Hiđro - \(H_2\)

Heli - \(He\)

Oxi - \(O_2\)

Ozon - \(O_3\)

Asenic pentaflorua - \(AsF_5\)

Asin - \(AsH_3\)

Amoniac - \(NH_3\)

Metan - \(CH_4\)

Etan - \(C_2H_6\)

Etilen - \(C_2H_4\)

Axetilen - \(C_2H_2\)

Boran - \(BH_3\)

Điboran - \(B_2H_6\)

Nitơ - \(N_2\)

Flo - \(F_2\)

Clo - \(Cl_2\)

Clo monoflorua - \(ClF\)

Photpho nitrua - \(PN\)

Cacbon đioxit - \(CO_2\)

Cacbon monoxit - \(CO\)

Bis(triflometyl)peroxit - \(\left(CF_3\right)_2O_2\)

Niken cacbonyl - \(NiC_4O_4\)

Lưu huỳnh đioxit - \(SO_2\)

Lưu huỳnh hexaflorua - \(SF_6\)

Thiothionylflorua - \(S_2F_2\)

1) I played soccer last monday 

I difn't play soccer last monday 

?) Did you play soccer last monday ? 

2) We watched a soccer match last night 

We didn't watch a soccer match last night 

?) Did you watch a soccer match last night ? 

3) They listened to music 2 days ago 

They didn't listen to music 2 days ago 

Did they listen to music 2 days ago ? 

4) He sent me an email last week

 He didn't send me an email last week

Did he send you an email last week ? 

5) She told her mother a lie 

 She don't tell her mother a lie 

Did she tell her mother a lie ? 

EX1: Chia động từ ở quá khứ đơn

1. I (play) soccer last Monday

+) i played soccer last Monday

-)  i didn't play soccer last monday

?) Did you play soccer last monday ?

2. We (watch) a soccer match last night.

+) we watched a soccer ....

-) we didn't watch a soccer....

?) Did you watch a soccer ..... ?

3. They (listen) to music 2 days ago

+) They listened to music.....

-) they didn't listen to music.....

?). Did they listen to music .... ?

4. He (send) me an email last week

+) he sent me an email....

-) he didn't send me an email .....

?) did he send you an email ..... ?

5. She (tell) her mother a lie

+) she told her mother....

-) she didn't tell her mother...

?did she tell her mother ....?

Con của ông hàng xóm :Đ

Chắc là con của ông hàng xóm

Học tốt!!!

Trả lời

Bình thường hoặc ngủ hay thức mình cũng chẳng bt

HT

aak tui nghĩ là bình thường