#? C_6H_6+? O_2 -> ? CO_2 + ? H_2O# using the smallest possible integers. The coefficient of H2O is

1 Answer
Mar 28, 2018

#6#

Explanation:

#"C"_6"H"_6 + "O"_2 -> "CO"_2 + "H"_2"O"#

Balance carbon atoms

#"C"_6"H"_6 + "O"_2 -> 6"CO"_2 + "H"_2"O"#

Balance hydrogen atoms

#"C"_6"H"_6 + "O"_2 -> 6"CO"_2 + 3"H"_2"O"#

Balance oxygen atoms

#"C"_6"H"_6 + 15/2"O"_2 -> 6"CO"_2 + 3"H"_2"O"#

Equation is balanced, but here #15/2# is not an integer. So multiply #2# on both the sides

#2"C"_6"H"_6 + [cancel"2" xx 15/cancel"2""O"_2] -> 12"CO"_2 + 6"H"_2"O"#

#color(blue)(2"C"_6"H"_6 + 15"O"_2 -> 12"CO"_2 + 6"H"_2"O")#

Coefficient of #"H"_2"O"# is #6#.