Respuesta :
Answer : The mass of aluminium (Al) is 0.413 g
Solution : Given,
Volume of [tex]H_{2}(g)[/tex] at STP = 513 ml = 0.513 L ( 1 L = 1000 ml )
Molar mass of aluminium = 26.98 g/mole
First we have to calculate the moles of [tex]H_{2}(g)[/tex].
At STP,
1 mole occupies 22.4 L volume
now, 0.513 L gives [tex]\frac{1mole\times0.513L}{22.4L}[/tex] moles of [tex]H_{2}(g)[/tex]
The moles of [tex]H_{2}(g)[/tex] = 0.0229 moles
The Net balanced chemical reaction is,
[tex]2Al(s)+6HCl(aq)\rightarrow 2AlCl_3(aq)+3H_2(g)[/tex]
From the balanced chemical reaction, we conclude that
2 moles of Aluminium (Al) produces 3 moles of hydrogen gas
Now the number of moles of aluminium required in 0.0229 moles of hydrogen gas = [tex]\frac{2moles\times 0.0229moles}{3moles}[/tex] = 0.0153 moles
Now we have to calculate the mass of aluminium.
Mass of aluminium = number of moles × Molar mass = 0.0153 moles × 26.98 g/mole = 0.413 g
The mass of aluminium required is 0.413 g.
