Consider the balanced equation.
n2 + 3h2 mc033-1.jpg 2nh3
what is the percent yield of nh3 if the reaction of 26.3 g of h2 produces 79.0 g of nh3?

The balanced chemical reaction is:

N2 + 3H2 = 2NH3 

We are given the amount of H2 being reacted. This will be our starting point.

26.3 g H2 (1 mol H2 / 2.02 g H2) 2 mol O2/3 mol H2) ( 17.04 g NH3 / 1mol NH3) = 147.90 g O2

Percent yield = actual yield / theoretical yield x 100

Percent yield = 79.0 g / 147.90 g x 100

Percent yield = 53.4%

o conteúdo de calor de um sistema é igual à entalpia apenas para um sistema que é constante