When aluminum is placed in concentrated hydrochloric acid, hydrogen gas is produced. 2 Al ( s ) + 6 HCl ( aq ) ⟶ 2 AlCl 3 ( aq ) + 3 H 2 ( g ) What volume of H 2 ( g ) is produced when 2.80 g Al ( s ) reacts at STP?

Respuesta :

Answer:

3.49 Liters of hydrogen is produced when 2.80 grams of aluminum reacts at STP.

Explanation:

[tex]2Al ( s ) + 6HCl ( aq )\rightarrow 2AlCl_3 ( aq) +3H_2 ( g )[/tex]

Moles of aluminum = [tex]\frac{2.80 g}{27 g/mol}=0.1037 mol[/tex]

According to reaction , 2 moles of aluminium gives 3 moles of hydrogen gas.Then 0.1037 moles of aluminum will give:

[tex]\frac{3}{2}\times 0.1037 mol=0.1556 mol[/tex] of hydrogen gas

Moles of hydrogen gas = n = 0.1556 mol

Pressure of the gas, at STP  , P = 1 atm

Temperature of the gas, at STP = T = 273 K

Volume of the gas , At STP = V

[tex]PV=nRT[/tex] ( Ideal gas equation )

[tex]V=\frac{nRT}{P}=\frac{0.1556 mol\times 0.08210 atm L/mol K\times 273 K}{1 atm}=3.49 L[/tex]

3.49 Liters of hydrogen is produced when 2.80 grams of aluminum reacts at STP.