Technical calcium carbide contains 80% CaC2. How much acetylene is obtained from 20 g of such carbite?

Let’s write the reaction equation:

CaC2 + 2H2O = Ca (OH) 2 + C2H2 ↑

Let’s find the mass of calcium carbide:

m (CaC2) = m (CaC2) technical * w (CaC2) / 100 = 20 * 80/100 = 16 (g).

Let’s find the amount of calcium carbide substance:

v (CaC2) = m (CaC2) / M (CaC2) = 16/64 = 0.25 (mol).

According to the reaction equation, from 1 mol of CaC2, 1 mol of C2H2 is formed, therefore:

v (C2H2) = v (CaC2) = 0.25 (mol).

Thus, the volume of acetylene formed, measured under normal conditions (n.o.):

V (C2H2) = v (C2H2) * Vm = 0.25 * 22.4 = 5.6 (l).

Answer: 5.6 l.