Bài 7:

\(a.m_{Fe}=0,5.56=28\left(g\right)\\ b.n_{p.tử}=\dfrac{6.10^{23}}{6.10^{23}}=1\left(mol\right)\\ m_{CO_2}=44.1=44\left(g\right)\\ m_{Al_2O_3}=1.102=102\left(g\right)\\ m_{C_6H_{12}O_6}=180.1=180\left(g\right)\\ m_{H_2SO_4}=98.1=98\left(g\right)\)

Bài 8:

\(a.n_{Ca}=\dfrac{112}{40}=2,8\left(mol\right)\\ b.m_{HCl}=36,5.0,5=18,25\left(g\right)\\ c.n_{H_2SO_4}=\dfrac{49}{98}=0,5\left(mol\right)\)

=> m_N=n_N.14=0,3.14=4,2(g)

Nãy lỗi mạng quá

\(a.n_{N_2O}=\dfrac{8,8}{44}=0,2\left(mol\right)\\ \Rightarrow n_N=2n_{N_2O}=0,4\left(mol\right)\\ \Rightarrow m_N=0,4.14=5,6\left(g\right)\\ b.n_N=2n_{NH_4NO_3}=\dfrac{2.6.10^{23}}{6.10^{23}}=2\left(mol\right)\\ \Rightarrow m_N=2.14=28\left(g\right)\\ c.n_N=n_{NO}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\\ \Rightarrow m_N=0,3.14=4,2\left(g\right)\)

\(m_{Ca}=\dfrac{40}{12}.1,9926.10^{-23}=6,642.10^{-23}\left(g\right)\)

a) $n_{H_2SO_4} = 0,1.4,8 = 0,48(mol)$
$Al_2O_3 + 3H_2SO_4 \to Al_2(SO_4)_3 + 3H_2O$
$n_{Al_2O_3} = \dfrac{1}{3}n_{H_2SO_4} =0,16(mol)$
$m = 0,16.102 = 16,32(gam)$

b)

$n_{Al_2(SO_4)_3} = n_{Al_2O_3} = 0,16(mol)$
$m_{muối} = 0,16.342 = 54,72(gam)$

c)

$Al_2O_3 + 2KOH \to 2KAlO_2 + H_2O$
$n_{KOH} = 2n_{Al_2O_3} = 0,32(mol)$
$V_{dd\ KOH} = \dfrac{0,32}{4,8} = 0,067(lít)$

Ta có: \(n_{H_2SO_4}=0,1.4,8=0,48\left(mol\right)\)

PT: \(Al_2O_3+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2O\)

___0,16_____0,48______0,16 (mol)

a, m = m_Al2O3 = 0,16.102 = 16,32 (g)

b, m_Al2(SO4)3 = 0,16.342 = 54,72 (g)

c, \(Al_2O_3+2KOH\rightarrow2KAlO_2+H_2O\)

____0,16____0,32 (mol)

\(\Rightarrow V_{ddKOH}=\dfrac{0,32}{4,8}=\dfrac{1}{15}\left(l\right)\)

Bạn tham khảo nhé!

Theo ĐLBTKL thì

m _Al + m _O2 = m _Al2O3

10,8 + 9,6 = a

=> a = 20,4 g

giup mk voi

a. Ta có : C = 12 đvC = 1,9926.10-23 (g)

 => 1 đvC = (1,9926.10^-23) : 12 ≈ 1,66.10^-24 (g).

b. Khối lượng tính bằng gam của nguyên tử nhôm là :

    m_Al = 27 đvC = 27. 1,66.10^-24 = 4,482.10^-23 (g)