Question

Caluculate the volume,mass,number of molecules and number of atoms of hydrogen iberated when 460g of sodium reacts with excess ofwater at stp

Answer 1

460 grams of water indicates 460/23 = 20moles of sodium

The reaction is,
                          2Na  +  2H₂O   ------------>  2NaOH  +  H₂

multiplying with 10, we get
                          20Na  +  20H₂O   ------------>  20NaOH  +  10H₂

So 460 grams of sodium on reacting with water gives 10 moles of Hydrogen gas.

Now this 10 moles of hydrogen is nothing but

→10 x 22.4 = 224 litres of hydrogen gas
→10 x 2 = 20grams of H₂ gas
→10 x Avogadro number(6 x 10²³) = 6 x 10²⁴ molecules of H₂
→2 x number of molecules = 1.2 x 10²⁵ atoms of H₂