How much acetylene can be obtained from 12.8 kg of technical calcium carbide containing 10% impurities?

Given:

m (CaC2) = 12 800 g

w% (impurities) = 10%

To find:

V (C2H2) -?

Decision:

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

1) Find the mass of pure calcium carbide:

if the proportion of impurities is 10%, then the proportion of pure substance is 90%

then m (CaC2) = 12 800 g * 0.1 = 1 280 g

2) Find the amount of calcium carbide:

n (CaC2) = m: M = 1 280 g: 64 g / mol = 20 mol

3) We compose a logical expression:

if 1 mole of CaC2 gives 1 mole of C2H2,

then 20 mol CaC2 will give x mol C2H2,

then x = 20 mol.

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

V (C2H2) = n * Vm = 20 mol * 22.4 L / mol = 448 L.

Answer: V (C2H2) = 448 l.