What role do the coefficients serve in a chemical reaction? coefficients balance the equation with respect to the law of conservation of energy. coefficients increase the products to increase the efficiency of the reaction. coefficients balance the equation with respect to the law of conservation of mass. coefficients increase the reactants to the reaction proceed.

)benzene and toluene form nearly ideal solutions. consider an equimolar solution of benzene and toluene. at 20 °c the vapour pressures of pure benzene and toluene are 9.9 kpa and 2.9 kpa, respectively. the solution is boiled by reducing the external pressure below the vapour pressure. calculate (i) the pressure when boiling begins, (ii) the composition of each component in the vapour, and (iii) the vapour pressure when only a few drops of liquid remain. assume that the rate of vaporization is low enough for the temperature to remain constant at 20 °c.