Question

Polchlorinated biphenyls (PCBs)?

the decomposition of (PCBs): 2C12H4Cl6 + 23O2 + 2H2O --> 24CO2 + 12HCL
a) How many moles of water are needed to react 10.0 mol O2?
b) How many grams of HCl are produced when 15.2 mol H2O react?
c) How many moles of CO2 are produced when 76.5g HCL are produced?
d) How many grams of C12H4Cl6 are reacted when 100.25g CO2 are produced?
e) How many grams of HCl are produced when 2.5kg C12H4Cl6 react?
(please show your work so I can understand)

Answer 1

Ans :

a) 2 moles of water react with 23 moles of O2 according to the balanced chemical reaction

So the number of moles of water required to react with 10 moles of water will be :

( 10 x 2) / 23

= 0.87 moles

b) 2 moles of water makes 12 moles of HCl

So 15.2 mol of H2O will make ( 15.2 x 12) / 2

= 91.2 moles of HCl

So the amount of HCl in grams will be = 91.2 x 36.46 = 3325.152 grams

c) 76.5 g of HCl = 76.5 / 36.46 = 2.1 moles

So the number of moles of CO2 = 2.1 x 2 = 4.2 moles

d) 100.25 g of CO2 = 100.25 / 44.01 = 2.28 moles

2 moles of C12H4Cl6 makes 24 moles of CO2

So the number of moles of C12H4Cl6 will be ( 2.28 x 2) / 24

= 0.19 moles

Amount of C12H4Cl6 in grams will be : 0.19 x 360.87816

= 68.6 grams

e) Number of moles of C12H4Cl6 = 2500/ 360.87816 = 6.93 moles

2 moles of C12H4Cl6 makes 12 moles of HCl

So 6.93 moles of C12H4Cl6 will make ( 6.93 x 12) /2 = 41.58 moles of HCl

The amount of HCl in grams = 41.58 x 36.46 = 1516 grams

Hope this helps !!