When propane, #C_3H_8#, is burned, carbon dioxide and water vapor are produced according to the following reaction: #C_3H_8 + 5O_2 -> 3CO_2 + 4H_2O#. How much propane is burned if 160.0 g of O2 are used and 132 g of CO2 and 72.0 g of H2O are produced?

1 Answer
Dec 19, 2016

Answer:

#C_3H_8+5O_2 rarr 3CO_2 + 4H_2O#

Precisely one mole, #44*g# of pentane, were combusted.

Explanation:

#"Moles of carbon dioxide:"# #(132*g)/(44.0*g*mol^-1)=3*mol#

#"Moles of water:"# #(72*g)/(18.01*g*mol^-1)=4*mol#

#"Moles of oxygen:"# #(160*g)/(32.0*g*mol^-1)=5*mol#

Because there were #3# #mol# carbon dioxide produced, and stoichiometric water, one mole precisely of propane was combusted.

If pentane were burned in excess dioxygen, and #220*g# carbon dioxide were produced, what was the starting mass of pentane?

#C_5H_12 + 8O_2 rarr 5CO_2 + 6H_2O#