Mass of B₂ = 18.75 g
Given
Element A and element B
Required
The reaction
mass of B₂
Solution
The balanced equation :
2A(s) + B₂(g) ⇒2AB(s)
mol AB :
= Molarity x Volume
= 2.5 M x 0.25 L
= 0.625
From the equation, mol ratio of B₂ : AB = 1 : 2, so mol B₂ :
= 1/2 x mol AB
= 1/2 x 0.625
= 0.3125
Mass B₂ (Molar mass = 2x30 g/mol=60 g/mol)
= mol x molar mass
= 0.3125 x 60 g/mol
= 18.75 g