Answer: 480 kJ of energy is released when 3.5 mol of [tex]C_2H_4[/tex] reacts.
Explanation:
The balanced chemical reaction is:
[tex]C_2H_4(g)+H_2(g)\rightarrow C_2H_6(g)[/tex] [tex]\Delta H=-137kJ[/tex]
Thus it is given that the reaction is exothermic (heat energy is released) as enthalpy change for the reaction is negative.
1 mole of [tex]C_2H_4[/tex] on reacting gives = 137 kJ of energy
Thus 3.5 moles of [tex]C_2H_4[/tex] on reacting gives = [tex]\frac{137}{1}\times 3.5=480 kJ[/tex] of energy
Thus 480 kJ of energy is released when 3.5 mol of [tex]C_2H_4[/tex] reacts.
