\(4Mg+10HNO_3\rightarrow4Mg\left(NO_3\right)_2+N_2O+5H_2O\)

=> 4 + 10 + 4 + 1 + 5 = 24 => Chọn B
\(5Zn+12HNO_3\rightarrow5Zn\left(NO_3\right)_2+N_2+6H_2O\)

=> 5 + 12 + 5 + 1 + 6 = 29 => Chọn D
\(8Al+30HNO_3\rightarrow8Al\left(NO_3\right)_3+3NH_4NO_3+9H_2O\)

=> 8 + 30 + 8 + 3 + 9 = 58 => Chọn A

\(2Al+6H_2SO_{4\left(\text{đ}\text{ặ}c\right)}\xrightarrow[]{t^o}Al_2\left(SO_4\right)_3+3SO_2+6H_2O\)

=> 2 + 6 + 1 + 3 + 6 = 18 => Chọn C

\(3Fe\left(OH\right)_2+10HNO_3\rightarrow3Fe\left(NO_3\right)_3+NO+8H_2O\)

=> 3 + 10 + 3 + 1 + 8 = 25 => Chọn D

\(2KMnO_4+16HCl\rightarrow2KCl+2MnCl_2+5Cl_2+8H_2O\)

=> 2 + 16 + 2 + 2 + 5 + 8 = 35 => Chọn C

\(4Na+O_2\xrightarrow[]{}2Na_2O\)

Na+ O2=Na2O

\(2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\uparrow\)

\(2:3:1:3\left(mol\right)\)

\(0,1:0,15:0,05:0,15\left(mol\right)\)

\(n_{H_2}=\dfrac{V}{22,4}=\dfrac{3,36}{22,4}=0,15\left(mol\right)\)

\(a,m_{Al}=n.M=0,1.27=2,7\left(kg\right)\)

\(b,m_{Al_2\left(SO_4\right)_3}=n.M=0,05.342=17,1\left(g\right)\)

n của Al2(SO4)3 = 0,5 

=» m = 0,5 . 342 chứ?

0,05 đâu ra vậy?

25.

\(n_{hh}=\dfrac{11,2}{22,4}=0,5\left(mol\right)\)

Gọi CTTQ của hai ankan đồng đăng kế tiếp là: \(C_{\overline{n}}H_{2\overline{n}+2}\)

=> \(\overline{M}_{hh}=\dfrac{24,8}{0,5}=49,6\)

Có: \(14\overline{n}+2=49,6\)

=> \(\overline{n}=3,4\) (với đk \(\overline{n}\) nguyên dương)

=> 2 ankan lần lượt là \(C_3H_8,C_4H_{10}\)

Gọi x: n \(C_3H_8\)

       y: \(n_{C_4H_{10}}\)

có:  

x + y = 0,5

44x + 58y = 24,8

=> x = 0,3

y = 0,2

=> \(\%_{V_{C_3H_8}}=\dfrac{0,3.22,4.100}{11,2}=60\%\)

=> \(\%_{V_{C_4H_{10}}}=100-60=40\%\)

Vậy chọn C.

$Ba(OH)_2 + CO_2 \to BaCO_3 + H_2O$

Theo PTHH : 

$n_{CO_2} = n_{BaCO_3} = \dfrac{29,55}{197} = 0,15(mol)$

$m_{H_2O} + m_{CO_2} = 29,55 - 19,35 = 10,2(gam)$

$\Rightarrow n_{H_2O} = 0,2(mol)$

Bảo toàn nguyên tố với C và H : 

$n_C = n_{CO_2} = 0,15(mol) ;n_H =2 n_{H_2O} = 0,4 (mol)$

Ta có : 

$n_C : n_H = 0,15 : 0,4 = 3 : 8$

Vậy hidrocacbon cần tìm là $C_3H_8$

Đáp án C

$CH_3-CH_2-CH_2-CH_2-CH_3 + Cl_2 \to CH_2Cl-CH_2-CH_2-CH_2-CH_3 + HCl$
$CH_3-CH_2-CH_2-CH_2-CH_3 + Cl_2 \to CH_3-CHCl-CH_2-CH_2-CH_3 + HCl$

$CH_3-CH_2-CH_2-CH_2-CH_3 + Cl_2 \to CH_3-CH_2-CHCl-CH_2-CH_3$

1/ Gọi CTTQ hai ankan là $C_nH_{2n+2}$
$C_nH_{2n+2} + \dfrac{3n+1}{2}O_2 \xrightarrow{t^o} nCO_2 + (n + 1)H_2O$
$n_{CO_2} = \dfrac{4,48}{22,4} = 0,2(mol)$

$n_{ankan} = \dfrac{1}{n}.n_{CO_2} = \dfrac{0,2}{n}(mol)$

$\Rightarrow \dfrac{0,2}{n}.(14n + 2) = 2,89$

$\Rightarrow n = 4,4$

Vậy hai ankan là $C_4H_{10}$ và $C_5H_{12}$

2/ $n_{C_4H_{10}} = a(mol) ; n_{C_5H_{12}} = b(mol)$

$\Rightarrow 58a + 72b = 2,89$
$n_{CO_2} = 4a + 5b = 0,2$

$\Rightarrow a = 0,025 ; b = 0,02$
$\%m_{C_4H_{10}} = \dfrac{0,025.58}{2,89}.100\% = 50,2\%$

Đặt \(\left\{{}\begin{matrix}M_X=3a\left(g/mol\right)\\M_Y=3,375a\left(g/mol\right)\\M_Z=7a\left(g/mol\right)\end{matrix}\right.\) và \(\left\{{}\begin{matrix}n_X=x\left(mol\right)\\n_Y=2x\left(mol\right)\\n_Z=3x\left(mol\right)\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}m_X=3ax\left(g\right)\\m_Y=3,375a.3x=6,75ax\left(g\right)\\m_Z=7a.3x=21ax\left(g\right)\end{matrix}\right.\)

\(\Rightarrow3ax+6,75ax+21ax=24,6\Leftrightarrow ax=0,8\)

\(\Rightarrow m_X=3.0,8=2,4\left(g\right)\)

\(n_{H_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)

Gọi hóa trị của X là n (n nguyên dương)

PTHH: \(2X+2nHCl\rightarrow2XCl_n+nH_2\)

            \(\dfrac{0,2}{n}\)<--------------------------0,1

\(\Rightarrow M_X=\dfrac{2,4}{\dfrac{0,2}{n}}=12n\left(g/mol\right)\)

Xét n = 2 thỏa mãn \(\Rightarrow M_X=12.2=24\left(g/mol\right)\)

\(\Rightarrow\left\{{}\begin{matrix}M_Y=\dfrac{3,375}{3}.M_X=27\left(g/mol\right)\\M_Z=\dfrac{7}{3}.M_X=56\left(g/mol\right)\end{matrix}\right.\)

Vậy ba kim loại X, Y, Z lần lượt là magie (Mg), nhôm (Al), sắt (Fe)

ko

A: CaO có thể có Ca

ddB: CaSO₄

D: SO₂

G: H₂

M: Ca(OH)₂

E: K₂SO₃, KHSO₃ 

\(2Ca+O_2\xrightarrow[]{t^o}2CaO\\ CaO+H_2SO_4\rightarrow CaSO_4+H_2O\\ Ca+2H_2SO_{4\left(\text{đ}\text{ặ}c\right)}\xrightarrow[]{t^o}CaSO_4+SO_2+2H_2O\)

\(2Na+2H_2O\rightarrow2NaOH+H_2\\ CaSO_4+2NaOH\rightarrow Ca\left(OH\right)_2\downarrow+Na_2SO_4\\ SO_2+2KOH\rightarrow K_2SO_3+H_2O\\ K_2SO_3+SO_2+H_2O\rightarrow2KHSO_3\\ 2KHSO_3+2NaOH\rightarrow Na_2SO_3+Na_2SO_3+2H_2O\\ K_2SO_3+BaCl_2\rightarrow BaSO_3\downarrow+2KCl\)

a, PT: \(Mg+2HCl\rightarrow MgCl_2+H_2\) (1)

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

\(2Cu+O_2\underrightarrow{t^o}2CuO\) (3)

\(CuO+2HCl\rightarrow CuCl_2+H_2O\) (4)

Gọi: \(\left\{{}\begin{matrix}n_{Mg}=x\left(mol\right)\\n_{Al}=y\left(mol\right)\\n_{Cu}=z\left(mol\right)\end{matrix}\right.\) ⇒ 24x + 27y + 64z = 1,384 (1)

Ta có: \(n_{H_2}=\dfrac{0,3584}{22,4}=0,016\left(mol\right)\)

Theo PT: \(n_{H_2}=n_{Mg}+\dfrac{3}{2}n_{Al}=x+\dfrac{3}{2}y=0,016\left(2\right)\)

\(n_{HCl\left(\left(1\right)+\left(2\right)\right)}=2n_{H_2}=0,032\left(mol\right)=n_{HCl\left(4\right)}\) \(n_{Cu}=n_{CuO}=\dfrac{1}{2}n_{HCl\left(4\right)}=0,016=z\left(3\right)\)

Từ (1), (2) và (3) \(\Rightarrow\left\{{}\begin{matrix}x=0,012\left(mol\right)\\y=\dfrac{1}{375}\left(mol\right)\\z=0,016\left(mol\right)\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}m_{Mg}=0,012.24=0,288\left(g\right)\\m_{Al}=\dfrac{1}{375}.27=0,072\left(g\right)\\m_{Cu}=0,016.64=1,024\left(g\right)\end{matrix}\right.\)

b, \(C_{M_{HCl}}=\dfrac{0,032}{0,32}=0,1\left(M\right)\)