Question

1.15g of metallic Na react with excess of water . How many moles of H2 are formed and what volume of H2 is formed at S.T.P ?

Answer 1

2Na + 2H₂O ---------> 2NaOH + H₂

From the balanced equation, 2 moles of sodium metal (Na) produces one mole of hydrogen gas (H₂).

Therefore (2X23) g of Na produces 1 mole of hydrogen. 1.15g of Na will produce;

(1.15x1)/46= 0.025 moles of hydrogen.

Molar gas volume at stp is 22.4 L.

Therefore 0.025x 22.4

=0.56 L of hydrogen are produced.