Question

Gaseous ethane(CH3CH3) will react with gaseous oxygen(O2) to produce gaseous carbon dioxide(CO2) and gaseous water(H2O) . Suppose 0.902 g of ethane is mixed with 2.0 g of oxygen. Calculate the maximum mass of water that could be produced by the chemical reaction. Be sure your answer has the correct number of significant digits.

Answer 1

The balanced equation is as follows
2 C2H6 + 7 O2 -----------------------------------> 4 CO2 + 6 H2O

no of moles = mass / molar mass

ethane moles = 0.902g / 30.07 g/mol = 0.03 moles

oxygen moles = 2.0g / 32 g/mol = 0.0625 moles

2 moles c2h6 -----------------------------------> 6 moles h2o

0.03moles -----------------------------------------> ?

=> 0.03*6 / 2 = 0.09moles

7 moles o2 -----------------------------------> 6 moles h2o

0.0625 moles -------------------------------> ?

=> 0.0625 *6 / 7 = 0.05357 moles

limitting reactant is O2

maximum mass of h2o = 0.05357*18 = 0.9643 grams

answer = 0.964g