# From acetylene with a volume of 25 liters, benzene with a mass of 16 g was obtained.

**From acetylene with a volume of 25 liters, benzene with a mass of 16 g was obtained. What is the mass fraction of the benzene yield?**

Given:

V (C2H2) = 25 l

m (C6H6) = 16 g

Find:

% (practical C6H6) -?

Solution:

3C2H2 – (active coal) -> C6H6, – we solve the problem based on the composed reaction equation:

1) Find the amount of acetylene that has reacted:

n (C2H2) = V: Vm = 25 L: 22.4 L / mol = 1.12 mol

2) We compose a logical expression:

if 3 mol of C2H2 gives 1 mol of C6H6,

then 1.12 mol of C2H2 will give x mol of C6H6,

then x = 0.37 mol.

3) Find the mass of benzene formed during the reaction:

m (C6H6) = n * M = 0.37 mol * 78 g / mol = 28.86 g

4) Find the practical benzene yield:

w% (C6H6 practical) = 16 g: 28.86 g * 100% = 55.4%.

Answer: w% (C6H6 practical) = 55.4%.