ABS plastic is a polymer consisting of three monomer units: acrylonitrile (C₃H₃N), butadiene (C₄H₆), and styrene (C₈H₈). A sample of ABS plastic contains 12.9% N by mass. It took 1.56 g of Br₂ to react completely with a 2.00 g sample of ABS plastic. Bromine reacts 1:1 (by moles) with the butadiene units in the polymer and nothing else, so bromination is a method for determining the quantity of butadiene in the polymer. What is the percent by mass of styrene in the polymer?

Which of the following is always a reactant in a combustion reaction? oxygen nitrogen hydrogen carbon

)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.

Apound is approximately 0.45 kilogram. a persons weighs 87 kilograms. what is the persons’s weight, in pounds, when expressed to the correct number of significant figures