Alkadiene with a mass of 13.6 g can add a maximum of 8.96 liters of hydrogen.

Alkadiene with a mass of 13.6 g can add a maximum of 8.96 liters of hydrogen. Establish the molecular formula of the alkadiene.

CnH2n-2 + 2H2 = CnH2n + 2.

Alkadiene is converted to alkane by attaching the maximum amount of hydrogen. Knowing that 1 mole of gas at normal conditions occupies a volume of 22.4 liters, we find the amount of hydrogen substance:

n = 8.96 / 22.4 = 0.4 mol.

The mass of hydrogen is:

m = n * Mr = 0.4 * 2 = 0.8 g.

Because given the mass of alkadiene in the condition of the problem, according to the proportion you can find its molar mass:

13.6 g – 0.8 g

x g – 4 g.

Hence x = 68 g.

So 12n + 2n – 2 = 68,

14n = 70,

n = 5.

The alkadiene formula is C5H8.