Polyethylene is a polymer consisting of only carbon and hydrogen.If 2.300 g of the polymer is burned in oxygen it produces 2.955 g of H₂O and 7.217 g of CO₂.Determine the empirical formula of polyethylene.

Question

Quizplus · Accepted Answer

To determine the empirical formula, we need to find the ratio of carbon and hydrogen atoms in the polymer. First, we need to calculate the amount of carbon and hydrogen in the polymer. We know that the only products of the combustion are H₂O and CO₂, which means that all the carbon and hydrogen in the polymer have been converted into these two compounds. From H₂O, we can see that there is 1 carbon atom and 2 hydrogen atoms for every oxygen atom. Therefore, the amount of carbon and hydrogen from the polymer that contribute to H₂O are: Carbon = 2.955 g / (32.06 g/mol) = 0.092 moles Hydrogen = 2 x 0.092 moles = 0.184 moles Similarly, from CO₂, we can see that there is 1 carbon atom and 1 oxygen atom for every sulfur atom. Therefore, the amount of carbon and hydrogen from the polymer that contribute to CO₂ are: Carbon = 7.217 g / (44.01 g/mol) = 0.164 moles Oxygen = 7.217 g / (32.06 g/mol) = 0.225 moles Now we can calculate the ratio of carbon to hydrogen: Carbon/Hydrogen = (0.092 moles / 0.184 moles) = 0.5 This means that there are equal number of carbon and hydrogen atoms in the polymer. The only choice that represents this ratio of atoms is B: CH₂.

Polyethylene Is a Polymer Consisting of Only Carbon and Hydrogen