From 100 liters of acetylene, 64 g of benzene were obtained. Calculate the mass fraction of the yield

From 100 liters of acetylene, 64 g of benzene were obtained. Calculate the mass fraction of the yield of the reaction product from the theoretically possible.

Given:

V (C2H2) = 100 L;

m (C6H6) = 64 g;

Find:

w% (C6H6 practical) -?

Solution:

1) We compose the reaction equation according to the condition of the problem:

3C2H2 – (act. C, cyclic trimerization) -> C6H6;

2) Find the amount of acetylene contained in 100 liters of gas:

n (C2H2) = V: Vm = 100 L: 26 L / mol = 3.846 mol;

3) We compose logical equality:

if 3 mol C2H2 gives 1 mol C6H6,

then 3.846 mol C2H2 will give x mol C6H6,

then x = 1.282 mol.

4) Find the theoretically possible benzene yield:

m (C6H6) = n * M = 1.282 mol * 78 g / mol = 100 g;

5) Find the practical percentage of product yield:

w% (C6H6 practical) = 64 g: 100 g * 100% = 64%.

Answer: w% (C6H6 practical) = 64%.