Answer to Question #179609 in Inorganic Chemistry for Alex

Question

______C2H6  +  ______O2  -->  ______CO2  +  _______H2O

Calculate the mass of carbon dioxide formed when 7.80 g of benzene (C2H6) burns.

Answer 1

2C₂H₆ + 7O₂ -------> 4CO₂ + 6H₂O

2C₆H₆ + 15O₂ -------> 12CO₂ + 6H₂O

(Formula for benzene is C₆H_6, we shall therefore work with the second equation)

Molar mass of benzene = 78 g/mol

Moles of benzene = 7.8 g/78 g/mol = 0.1 moles

From the balanced equation above, 2 moles of benzene burn in O₂ to form 12 moles of CO₂

Therefore, 0.1 moles of benzene burns in O₂ to form (12/2) x 0.1 = 0.6 moles of CO₂

Molar mass of CO₂ = 44 g/mol

Hence, mass of CO₂ formed = 0.6 moles x 44 g/mol = 26.4 g