Question

Consider the balanced reaction equation given below: 2 AgNO3 (aq) + CaCl2 (aq) --------> 2 AgCl (s) + Ca(NO3)2 (aq) What mass of calcium chloride will be needed to produce 2.35 x 1025 formula units of silver chloride?

Answer 1

2 AgNO3 (aq) + CaCl2 (aq) --------> 2 AgCl (s) + Ca(NO3)2 (aq)

formula units of AgCl = 2.35 x 10^25

moles of AgCl = 2.35 x 10^25 / 6.023 x 10^23

                       = 39.02 mol

from the balanced equation :

1 mol CaCl2 ---------------> 2 mol AgCl

     ??          ---------------> 39.02 mol AgCl

moles of CaCl2 = 39.02 x 1 /2 = 19.51

mass of CaCl2 = 19.51 x 110.984

                           = 2165 g

mass of calcium chloride = 2165 g