Gọi n là hóa trị cao nhất của kim loại Z

\(Z+\dfrac{n}{2}Cl_2\underrightarrow{t^o}ZCl_n\)

\(n_Z=\dfrac{2,275}{Z}\)

\(m_{ZCl_n}=\dfrac{2,275}{Z}.\left(Z+35,5n\right)=\dfrac{2,275Z+80,7625n}{Z}=4,76\)

Với n = 2 => Z = 65

Vậy kim loại cần tìm là Zn (kẽm)

Gọi CTHH cần tìm là N_xO_y

Ta có: M_NxOy = 54.2 = 108 (g/mol)

\(\Rightarrow x=\dfrac{108.25,93\%}{14}=2\)

Mà: 14x + 16y = 108

⇒ y = 5

Vậy: CTHH cần tìm là N_xO₅.

a, CTHH: O₂

M_O2 = 16.2 = 32 (g/mol)

b, CTHH: CaCO₃

M_CaCO3 = 40 + 12 + 16.3 = 100 (g/mol)

c, CTHH: Fe₂O₃

M_Fe2O3 = 56.2 + 16.3 = 160 (g/mol)

d, CTHH: Al(OH)₃

M_Al(OH)3 = 27 + (16 + 1).3 = 78 (g/mol)

16

a, Gọi: n_Fe2O3 = n_CuO = a (mol)

⇒ 160a + 80a = 24 ⇒ a = 0,1 (mol)

PT: \(CuO+H_2SO_4\rightarrow CuSO_4+H_2O\)

\(Fe_2O_3+3H_2SO_4\rightarrow Fe_2\left(SO_4\right)_3+3H_2O\)

Theo PT: \(n_{H_2SO_4}=n_{CuO}+3n_{Fe_2O_3}=0,4\left(mol\right)\)

\(\Rightarrow C_{M_{H_2SO_4}}=\dfrac{0,4}{0,5}=0,8\left(M\right)\)

b, Theo PT: \(\left\{{}\begin{matrix}n_{CuSO_4}=n_{CuO}=0,1\left(mol\right)\\n_{Fe_2\left(SO_4\right)_3}=n_{Fe_2O_3}=0,1\left(mol\right)\end{matrix}\right.\)

⇒ m _muối = m_CuSO4 + m_Fe2(SO4)3 = 0,1.160 + 0,1.400 = 56 (g)

c, \(C_{M_{CuSO_4}}=C_{M_{Fe_2\left(SO_4\right)_3}}=\dfrac{0,1}{0,5}=0,2\left(M\right)\)

a, \(Zn+2HCl\rightarrow ZnCl_2+H_2\)

\(2Al+6HCl\rightarrow2AlCl_3+3H_2\)

b, \(n_{Al}=\dfrac{5,4}{27}=0,2\left(mol\right)\)

\(n_{HCl}=0,5.2,1=1,05\left(mol\right)\)

Theo PT: \(n_{HCl}=2n_{Zn}+3n_{Al}\Rightarrow n_{Zn}=0,225\left(mol\right)\)

⇒ m_Zn = 0,225.65 = 14,625 (g)

\(n_{H_2}=\dfrac{1}{2}n_{HCl}=0,525\left(mol\right)\Rightarrow V_{H_2}=0,525.24,79=13,01475\left(l\right)\)

c, Theo PT: \(\left\{{}\begin{matrix}n_{ZnCl_2}=n_{Zn}=0,225\left(mol\right)\\n_{AlCl_3}=n_{Al}=0,2\left(mol\right)\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}C_{M_{ZnCl_2}}=\dfrac{0,225}{0,5}=0,45\left(M\right)\\C_{M_{AlCl_3}}=\dfrac{0,2}{0,5}=0,4\left(M\right)\end{matrix}\right.\)

đổi 1 tấn = 1000 kg

Pt CaCO₃ -> CaO + CO₂ 

Số mol CaCO₃ : 1000 : 100 = 1 mol 

=> nCaCO₃ = nCaO = nCO₂ 

Khối lượng CaO \(m=n.M.90\%=\dfrac{252}{5}\left(kg\right)\)

Thể tích CO₂ : \(V=n.22,4.90\%=20,16\left(l\right)\)

\(n_{H_2SO_4}=0,1.0,1=0,01\left(mol\right)\)

\(Na_2O+H_2SO_4\rightarrow Na_2SO_4+H_2O\)

0,1<-----0,1

\(a=m_{Na_2O}=0,1.62=6,2\left(g\right)\)

\(n_{Zn}=\dfrac{13}{65}=0,2\left(mol\right)\)

\(n_{Fe_2O_3}=\dfrac{16}{160}=0,1\left(mol\right)\)

a.

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

0,2------------------------>0,2

\(3H_2+Fe_2O_3\underrightarrow{t^o}2Fe+3H_2O\)

0,2------------>  \(\dfrac{2}{15}\)

b) \(V_{H_2\left(đkc\right)}=0,2.24,79=4,958\left(l\right)\)

c) 

Lập tỉ lệ: \(\dfrac{0,2}{3}>\dfrac{0,1}{1}\Rightarrow Fe_2O_3dư\)

\(m_{Fe}=\dfrac{2}{15}.56=7,47\left(g\right)\)

\(n_{H_2}=\dfrac{3,7185}{24,79}=0,15\left(mol\right)\)

\(Na+H_2O\rightarrow NaOH+\dfrac{1}{2}H_2\)

x -------------->x --------->0,5x

\(K+H_2O\rightarrow KOH+\dfrac{1}{2}H_2\)

y------------>y--------->0,5y

\(\left\{{}\begin{matrix}23x+39y=8,5\\0,5x+0,5y=0,15\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=0,2\\y=0,1\end{matrix}\right.\)

\(6NaOH+Fe_2\left(SO_4\right)_3\rightarrow3Na_2SO_4+2Fe\left(OH\right)_3\)

0,2------------------------------------------->\(\dfrac{1}{15}\)

\(6KOH+Fe_2\left(SO_4\right)_3\rightarrow3Na_2SO_4+2Fe\left(OH\right)_3\)

0,1------------------------------------------> \(\dfrac{1}{30}\)

\(m_{Fe\left(OH\right)_3}=\left(\dfrac{1}{15}+\dfrac{1}{30}\right).107=10,7\left(g\right)\)

\(n_{H_2}=\dfrac{1,2395}{24,79}=0,05\left(mol\right)\)

\(\Rightarrow n_{H_2SO_4}=n_{H_2}=n_{SO_4^{2-}}=0,05\left(mol\right)\)

\(\Rightarrow m_{muối}=m_{kl}+m_{SO_4^{2-}}=2,43+0,05.96=7,23\left(g\right)\)

=> Đáp án D