Question

What mass of carbon

dioxide (in grams) is formed from the combustion

of 98.45 g of

C

7

H

12

O

2

(g)? Assume oxygen is in excess.

Answer 1

molar mass of C7H12O2 = 128 g/mol
number of mole of C7H12O2 = (given mass)/(molar mass)
= 98.45/128
= 0.769 mole

reaction taking place
C7H12O2 + 9O2 -- > 7CO2 + 6H2O
according to reaction
1 mole of C7H12O2 give 7 mole of CO2
0.769 mole of C7H12O2 give (7*0.769) mole of CO2
0.769 mole of C7H12O2 give 5.38 mole of CO2
number of mole of CO2 obtained = 5.38 mole
mass of CO2 obtained = (number of mole of CO2)*(molar mass of CO2)
molar mass of CO2 = 44 g/mol
mass of CO2 obtained = 5.38*44
= 236.8 g

Answer : 236.8 g