# C7H12 reacts with O2 to produce CO2 and H2O. Suppose 348 g of CO2 are produced in this reaction. What mass of O2 reacted?

Apr 11, 2016

398 g

#### Explanation:

${C}_{7}$ ${H}_{16}$ + 11 ${O}_{2}$ ------> 7 C${O}_{2}$ + 8 ${H}_{2}$O

As per the chemical equation for the combustion of
Heptane , ${C}_{7}$ ${H}_{12}$ , for burning one mole of Heptane
eleven moles of Oxygen is needed and 7 moles of Carbon dioxide is released.

In terms of mass, 11 moles of Oxygen, ( 11 x 32 g = 352 g ) of Oxygen is needed to produce , 7 moles of Carbon Dioxide,
( 7 x 44 g = 308 g ) of Carbon dioxide is produced.

To produce 348 g of Carbon dioxide, we will need ,

= 352 g of ${O}_{2}$ x 348 g of C ${O}_{2}$ / 308 g of C${O}_{2}$

= 397.7 g of ${O}_{2}$