Question #1bbbc

1 Answer
Jan 17, 2017

Answer:

You will require a sample of impure #CaC_2# that is 10.02 g in mass.

Explanation:

The equation for acetylene production is

#CaC_2 + 2H_2O rarr C_2H_2 + Ca(OH)_2#

At STP, 3.36 L of any gas represents #3.36-:22.4 = 0.15 mol#

Since the ratio between #CaC_2# and #C_2H_2# is 1 to 1 in the equation, we require 0.15 mol of calcium carbide to do the job.

The molar mass of #CaC_2# is 64.1 g, so 0.15 mol would have a mass of 9.615 g.

Since the sample is 4% impure, the 9.615 g must represent 96% of the mass of the impure sample, so the sample must be

#9.615 -: 0.96 = 10.02 g# in size.