Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
![](https://rs.olm.vn/images/avt/0.png?1311)
a)CuO+H2SO4--->CuSO4+H2O
b) Ta có
n CuO=3,2/80=0,04(mol)
Theo pthh
n H2SO4=n CuO=0,04(mol)
m dd H2SO4=\(\frac{0,04.98.100}{4,9}=80\left(g\right)\)
m dd sau pư=m CuO+m CuSO4=80+3,2=83,2(g)
n CuSO4=0,04(mol)
C% CuSO4=\(\frac{0,04.160}{83,2}.100\%=7,7\%\)
![](https://rs.olm.vn/images/avt/0.png?1311)
Ta có: \(n_{NaOH}=\dfrac{12}{40}=0,3\left(mol\right)\)
PT: \(2NaOH+CuCl_2\rightarrow2NaCl+Cu\left(OH\right)_{2\downarrow}\)
_____0,3_______________________0,15 (mol)
\(Cu\left(OH\right)_2\underrightarrow{t^o}CuO+H_2O\)
0,15_______0,15 (mol)
⇒ m = mCuO = 0,15.80 = 12 (g)
Bạn tham khảo nhé!
![](https://rs.olm.vn/images/avt/0.png?1311)
\(n_{Fe_2O_3}=\dfrac{16}{160}=0,1\left(mol\right)\)
PTHH: Fe2O3 + 3H2SO4 → Fe2(SO4)3 + 3H2O
Mol: 0,1 0,1
\(m_{Fe_2\left(SO_4\right)_3}=0,1.400=40\left(g\right)\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(n_{Cu}=\dfrac{6,4}{64}=0,1\left(mol\right);n_{NaOH}=1\cdot0,3=0,3\left(mol\right)\\ PTHH:Cu+H_2SO_{4\left(đ\right)}\rightarrow CuSO_4+H_2O+SO_2\uparrow\\ SO_2+2NaOH\rightarrow Na_2SO_3+H_2O\\ \Rightarrow n_{SO_2}=n_{Cu}=0,1\left(mol\right)\\ \text{Vì }\dfrac{n_{SO_2}}{1}< \dfrac{n_{NaOH}}{2}\Rightarrow NaOH\text{ dư}\\ \Rightarrow n_{Na_2SO_3}=n_{SO_2}=0,1\left(mol\right)\\ \Rightarrow m_{muối}=m_{Na_2SO_3}=0,1\cdot126=12,6\left(g\right)\)
Chọn C
![](https://rs.olm.vn/images/avt/0.png?1311)
nZnO=8,1/81=0,1(mol)
PTHH: ZnO + H2SO4 -> ZnSO4 + H2O
0,1________0,1_____0,1(mol)
a) mH2SO4=0,1.98=9,8(g)
=> mddH2SO4=(9,8.100)/10=98(g)
b) mZnSO4=0,1.161=16,1(g)
mddZnSO4=mZnO+ mddH2SO4= 8,1+98= 106,1(g)
=> C%ddZnSO4= (16,1/106,1).100= 15,174%
![](https://rs.olm.vn/images/avt/0.png?1311)
Câu 3:
Gọi x, y lần lượt là số mol của MgO và Al2O3
Ta có: \(n_{H_2SO_4}=0,2.250:1000=0,05\left(mol\right)\)
a. PTHH:
MgO + H2SO4 ---> MgSO4 + H2O (1)
Al2O3 + 3H2SO4 ---> Al2(SO4)3 + 3H2O (2)
b. Theo PT(1): \(n_{H_2SO_4}=n_{MgO}=x\left(mol\right)\)
Theo PT(2): \(n_{H_2SO_4}=3.n_{Al_2O_3}=3y\left(mol\right)\)
=> x + 3y = 0,05 (1)
Theo đề, ta có: 40x + 102y = 1,82 (2)
Từ (1) và (2), ta có HPT:
\(\left\{{}\begin{matrix}x+3y=0,05\\40x+102y=1,82\end{matrix}\right.\)
=> x = 0,02, y = 0,01
=> \(m_{MgO}=0,02.40=0,8\left(mol\right)\)
=> \(\%_{m_{MgO}}=\dfrac{0,8}{1,82}.100\%=43,96\%\)
\(\%_{m_{Al_2O_3}}=100\%-43,96\%=56,04\%\)
Câu 4:
Ta có: \(m_{H_2SO_4}=\dfrac{19,6\%.100\%}{100}=19,6\left(g\right)\)
=> \(n_{H_2SO_4}=\dfrac{19,6}{98}=0,2\left(mol\right)\)
Ta lại có: \(n_{CuO}=\dfrac{8}{80}=0,1\left(mol\right)\)
a. PTHH: CuO + H2SO4 ---> CuSO4 + H2O
Ta thấy: \(\dfrac{0,1}{1}< \dfrac{0,2}{1}\)
Vậy H2SO4 dư.
Theo PT: \(n_{CuSO_4}=n_{CuO}=0,1\left(mol\right)\)
=> \(m_{CuSO_4}=0,1.160=16\left(g\right)\)
Ta có: \(m_{dd_{CuSO_4}}=8+100=108\left(g\right)\)
=> \(C_{\%_{CuSO_4}}=\dfrac{16}{108}.100\%=14,81\%\)
Câu 5: Thiếu đề
![](https://rs.olm.vn/images/avt/0.png?1311)
Đặt CT chung 3 KL là R có hóa trị chung là n
\(PTHH:4R+nO_2\xrightarrow{t^o}R_2O_n\\ R_2O_n+nH_2SO_4\to R_2(SO_4)_n+nH_2O\\ \Rightarrow n_{H_2SO_4}=n_{H_2O}\\ \text {Bảo toàn KL: }m_{R_2O_n}+m_{H_2SO_4}=m_{R_2(SO_4)_3}+m_{H_2O}\\ \Rightarrow 2,8+98n_{H_2SO_4}=6,8+18n_{H_2SO_4}\\ \Rightarrow n_{H_2SO_4}=0,05(mol)\\ \Rightarrow V=V_{dd_{H_2SO_4}}=\dfrac{0,05}{1}=0,05(l)=50(ml)\\ \text {Ta có: }n_{O_2}=\dfrac{n_{R_2O_3}}{2}.n;n_{R_2O_3}=\dfrac{n_{H_2SO_4}}{n}\\ \Rightarrow n_{O_2}=\dfrac{n_{H_2SO4}}{2}=0,025(mol)\\ \Rightarrow m_{O_2}=0,025.32=0,8(g)\\ \text {Bảo toàn KL: }m=m_R+m_{O_2}=m_{R_2O_n}\\ \Rightarrow m=m_R=2,8-0,8=2(g)\)
\(CuO+H_2SO_4\rightarrow CuSO_4+H_2O\\ n_{H_2SO_4}=n_{CuO}=\dfrac{19,6}{98}=0,2\left(mol\right)\\ \Rightarrow a=m_{CuO}=0,2\cdot80=16\left(g\right)\)
n H2SO4 = \(\dfrac{19,6}{2+32+16.4}=0,2mol\)
\(CuO+H_2SO_4->CuSO_4+H_2O\)
0,2..........0,2
m CuO = 0,2.(64+16)=16 g
Vậy a =16