Combustion in chemistry we can use a system of linear equations to determine the coefficients neces- sary to balance a chemical equation. for example, the complete combustion of propene (cshe) with oxygen (o2) results in carbon dioxide (co2) and water (h2o). because the quantity of each element is conserved, we must have the same quantities of carbon (c), oxygen (o) and hydrogen (h) on each side of the following chemical equation: a(c3hs) b(02) c(co2) + d(h20) where the coefficients a, b, c, d are how many of each molecule is present. (a) write the equation describing the conserved quantity of each type of chemical. you will have 3 equations in 4 unknowns. the equation for conserved oxygen atoms is given as an example: 2b = 2c + d ? 2b-2c-d = 0.