Question

5. The volume of hydrogen gas obtained at STP in litre when one gram of Al completely reacted with excess of aquos NaOH (Al=27] ​

Answer 1

Answer :-

1.232 Litres of hydrogen gas (H₂) is obtained at STP for the given reaction .

Explanation :-

2Al + 2NaOH + 2H₂O → 2NaAlO₂ + 3H₂

We are given with 1 gram of Aluminium, so number of moles of it will be :-

= Given Mass/Molar mass

= (1/27) mole

______________________________

From the balanced equation we have :-

∵ 2 moles of Al → 3 moles of H₂

∴ (1/27) moles of Al will give :-

= (1/27 × 3)/2

= 0.11/2

= 0.055 moles of H₂

Now we know that, at STP, one mole of a gas occupies 22.4 Litres . So, volume of Hydrogen gas obtained at STP will be :-

= 0.055 × 22.4

= 1.232 L