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19 tháng 12 2023

a, \(2Cu+O_2\underrightarrow{t^o}2CuO\)

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

b, \(\dfrac{m_{CuO}}{m_{MgO}}=\dfrac{2}{1}\Rightarrow\dfrac{n_{CuO}}{n_{MgO}}=\dfrac{2}{1}:\dfrac{80}{40}=1\)

⇒ nCuO = nMgO (1)

Có: m chất rắn tăng = mO2 = 32 (g)

Theo PT: \(n_{O_2}=\dfrac{1}{2}n_{CuO}+\dfrac{1}{2}n_{MgO}=\dfrac{32}{32}=1\left(mol\right)\left(2\right)\)

Từ (1) và (2) ⇒ nCuO = nMgO = 1 (mol)

⇒ mCuO = 1.80 = 80 (g)

mMgO = 1.40 = 40 (g)

16 tháng 8 2021

Đặt \(\left\{{}\begin{matrix}n_{Mg}=x\left(mol\right)\\n_{Fe}=y\left(mol\right)\end{matrix}\right.\)

Theo đề: \(m_{hh}=36\left(g\right)\)

\(\Rightarrow m_{Mg}+m_{Fe}=36\\ \Rightarrow24x+56y=36\left(1\right)\)

\(PTHH:2Mg+O_2\underrightarrow{t^o}2MgO\\ \left(mol\right)....x\rightarrow...0,5x.....x\\ PTHH:3Fe+2O_2\underrightarrow{t^o}Fe_3O_4\\ \left(mol\right)....y\rightarrow...\dfrac{2}{3}y....\dfrac{1}{3}y\)

Theo đề: \(n_{O_2}=\dfrac{13,44}{22,4}=0,6\left(mol\right)\)

\(\Rightarrow0,5x+\dfrac{2}{3}y=0,6\left(2\right)\)

\(\xrightarrow[\left(2\right)]{\left(1\right)}\left\{{}\begin{matrix}24x+56y=36\\0,5x+\dfrac{2}{3}y=0,6\end{matrix}\right.\\ \Leftrightarrow\left\{{}\begin{matrix}x=0,8\\y=0,3\end{matrix}\right.\\ \Rightarrow\left\{{}\begin{matrix}m_{Mg}=0,8.24=19,2\left(g\right)\\m_{Fe}=0,3.56=16,8\left(g\right)\end{matrix}\right.\\ m_r=m_{MgO}+m_{Fe_3O_4}=0,8.40+\dfrac{1}{3}.0,3.232=55,2\left(g\right)\)

 

16 tháng 8 2021

PTHH: C+O2→CO20,3mol:0,3mol→0,3molC+O2→CO20,3mol:0,3mol→0,3mol

S+O2→SO20,2mol:0,2mol→0,2molS+O2→SO20,2mol:0,2mol→0,2mol

mC=36%10100%=3,6(g)⇔nC=3,612=0,3(mol)mC=36%10100%=3,6(g)⇔nC=3,612=0,3(mol)

mS=10−3,6=6,4(g)⇔nS=6,432=0,2(mol)mS=10−3,6=6,4(g)⇔nS=6,432=0,2(mol)

VO2=(0,3+0,2)22,4=11,2(l)VO2=(0,3+0,2)22,4=11,2(l)

mhh=mCO2+mSO2=0,3.44+0,2.64=26(g)

12 tháng 2 2017

Coi hỗn hợp là Fe = x mol; Cu = y mol; S = z molO

mO = 1,6nO = 0,1

BTĐT: 3x + 2y = 2z + 2.0,09

Khối lượng X: 56x + 64y + 32z + 0,1.16 = 10

Mg + ddY (Fe2+; Cu2+; Mg (dư))

→ BT mol electron: 56x + 54y - (1,5x+y) .24 = 2,5

x = 0,08; y = 0,03; z = 0,06 (x,y,z xấp xỉ)

Bảo toàn e (Fe;Cu;S;O;O3; O2) V = 1,5616 (xấp xỉ)

Đáp án D

16 tháng 8 2021

Đặt \(\left\{{}\begin{matrix}n_{Al}=x\left(mol\right)\\n_{Fe}=y\left(mol\right)\end{matrix}\right.\)

Theo đề: \(m_{hh}=39\left(g\right)\)

\(\Rightarrow m_{Al}+m_{Fe}=39\\ \Rightarrow27x+56y=39\left(1\right)\)

\(PTHH:4Al+3O_2\underrightarrow{t^o}2Al_2O_3\\ \left(mol\right)....x\rightarrow..0.75x....0,5x\\ PTHH:3Fe+2O_2\underrightarrow{t^o}Fe_3O_4\\ \left(mol\right)....y\rightarrow..\dfrac{2}{3}y.....\dfrac{1}{3}y\)

Theo đề: \(n_{O_2}=\dfrac{V}{22,4}=\dfrac{12,32}{22,4}=0,55\left(mol\right)\)

\(\Rightarrow0,75x+\dfrac{2}{3}y=0,55\left(2\right)\)

\(\xrightarrow[\left(1\right)]{\left(2\right)}\left\{{}\begin{matrix}27x+56y=39\\0,75x+\dfrac{2}{3}y=0,55\end{matrix}\right.\\ \Leftrightarrow\left\{{}\begin{matrix}x=0,2\\y=0,6\end{matrix}\right.\\ \Rightarrow\left\{{}\begin{matrix}m_{Al}=0,2.27=5,4\left(g\right)\\m_{Fe}=0,6.56=33,6\left(g\right)\end{matrix}\right.\\ m_r=m_{Al_2O_3}+m_{Fe_3O_4}=0,5.0,2.102+\dfrac{1}{3}.0,6.232=56,6\left(g\right)\)

 

Gọi \(\left\{{}\begin{matrix}n_{Mg}=x\left(mol\right)\\x_{Ca}=y\left(mol\right)\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}24x+40y=17,6\\x=2y\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=0,4\\y=0,2\end{matrix}\right.\)

a)\(m_{Mg}=0,4\cdot24=9,6g\)

   \(m_{Ca}=0,2\cdot40=8g\)

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

   \(2Ca+O_2\underrightarrow{t^o}2CaO\)

Từ hai pt: \(\Rightarrow\Sigma n_{O_2}=\dfrac{1}{2}n_{Mg}+\dfrac{1}{2}n_{Ca}=\dfrac{1}{2}\cdot0,4+\dfrac{1}{2}\cdot0,2=0,3mol\)

\(\Rightarrow m_{O_2}=0,3\cdot32=9,6g\)

\(V_{O_2}=0,3\cdot22,4=6,72l\)

\(\Rightarrow V_{kk}=5V_{O_2}=5\cdot6,72=33,6l\)

4 tháng 3 2022

Chị ghi nhầm "nCa" thành "xCa" kìa

a) 

Có \(\left\{{}\begin{matrix}24.n_{Mg}+40.n_{Ca}=17,6\\n_{Mg}=2.n_{Ca}\end{matrix}\right.\)

=> \(\left\{{}\begin{matrix}n_{Ca}=0,2\left(mol\right)\\n_{Mg}=0,4\left(mol\right)\end{matrix}\right.\)

=> \(\left\{{}\begin{matrix}m_{Ca}=0,2.40=8\left(g\right)\\m_{Mg}=0,4.24=9,6\left(g\right)\end{matrix}\right.\)

b)

PTHH: 2Ca + O2 --to--> 2CaO 

            0,2-->0,1

             2Mg + O2 --to--> 2MgO

            0,4--->0,2

=> \(V_{O_2}=\left(0,1+0,2\right).22,4=6,72\left(l\right)\)

\(V_{kk}=6,72.5=33,6\left(l\right)\)

26 tháng 2 2023

Đặt \(\left\{{}\begin{matrix}n_{Mg}=a\left(mol\right)\\n_{Zn}=2a\left(mol\right)\\n_{Fe}=3a\left(mol\right)\end{matrix}\right.\)

Ta có: \(m_{t\text{ăng}}=m_{KL}-m_{H_2}\)

\(\Rightarrow m-m_{H_2}=m-2,4\\ \Leftrightarrow m_{H_2}=2,4\left(g\right)\Rightarrow n_{H_2}=\dfrac{2,4}{2}=1,2\left(mol\right)\)

PTHH:
`Mg + 2HCl -> MgCl_2 + H_2`

`Zn + 2HCl -> ZnCl_2 + H_2`

`Fe + 2HCl -> FeCl_2 + H_2`

Theo PTHH: 

\(n_{H_2}=n_{Mg}+n_{Zn}+n_{Fe}=a+2a+3a=6a\left(mol\right)\\ \Rightarrow6a=1,2\Leftrightarrow a=0,2\left(mol\right)\\ \Rightarrow\left\{{}\begin{matrix}n_{Mg}=0,2\left(mol\right)\\n_{Zn}=0,2.2=0,4\left(mol\right)\\n_{Fe}=0,2.3=0,6\left(mol\right)\end{matrix}\right.\)

Vậy \(m=0,2.24+0,4.65+0,6.56=64,4\left(g\right)\)

2 tháng 3 2023

 

Δ�=��−��2⇒�−2,4=�−��2⇔��2=2,4gam⇒��2=2,42=1,2mol

Gọi nMg là A => nZn là 2a, nFe là 3a

PTHH: \(C+O_2\xrightarrow[]{t^o}CO_2\)

              a___a______a    (mol)

            \(S+O_2\xrightarrow[]{t^o}SO_2\)

             b___b_______b   (mol)

Ta lập HPT: \(\left\{{}\begin{matrix}12a+32b=10\\a+b=\dfrac{11,2}{22,4}=0,5\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}a=0,3\\b=0,2\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}m_C=0,3\cdot12=3,6\left(g\right)\\m_S=6,4\left(g\right)\\V_{khí}=0,5\cdot22,4=11,2\left(l\right)\end{matrix}\right.\)

16 tháng 2 2022

Gọi số mol Al, Na trong a gam hỗn hợp là x, y (mol)

=> 27x + 23y = a (1)

PTHH: 4Al + 3O2 --to--> 2Al2O3

             x---------------->0,5x

            4Na + O2 --to--> 2Na2O

              y---------------->0,5y

=> 102.0,5x + 62.0,5y = 1,64.a

=> 51x + 31y = 1,64a (2)

(1)(2) => 51x + 31y = 1,64(27x + 23y)

=> 6,72x = 6,72y

=> x = y

\(\left\{{}\begin{matrix}\%m_{Al}=\dfrac{27x}{27x+23y}.100\%=54\%\\\%m_{Na}=\dfrac{23y}{27x+23y}.100\%=46\%\end{matrix}\right.\)