What volume of acetylene can be obtained by the interaction of water with 1 kg

What volume of acetylene can be obtained by the interaction of water with 1 kg of technical calcium carbide, the mass fraction of impurities in which is 20%?

Given:

m (CaC2) = 1 kg

w% (impurities) = 20%

To find:

V (C2H2) -?

Solution:

CaC2 + 2H2O = Ca (OH) 2 + C2H2, – we solve the problem, relying on the composed reaction equation:

1) Find the mass of pure calcium carbide:

if the proportion of impurities is 20%, then the proportion of pure substance is 80%,

then m (CaC2) = 1000 g * 0.8 = 800 g

2) Find the amount of calcium carbide:

n (CaC2) = m: M = 800 g: 64 g / mol = 12.5 mol

3) We compose a logical expression:

if 1 mol of CaC2 gives 1 mol of C2H2,

then 12.5 mol of CaC2 will give x mol of C2H2,

then x = 12.5 mol.

4) Find the volume of acetylene released during the reaction:

V (C2H2) = n * Vm = 12.5 mol * 22.4 L / mol = 280 L.

Answer: V (C2H2) = 280 l.