Question

A new employee for Pfizer, which manufactures a migraine with or without aura medication, is asked to monitor a reaction and determine if the correct compound has been made. The new chemist finds that when the compound of interest is isolated and combusted, CO2(g), H2O(g), and SO2(g) are released.

What is the identity of the other reactant used to combust the compound?

What are the possible elements in the compound of interest? Justify each choice.

The student finds that when 12.65 mg of the compound is combusted, 13.905 mg of gaseous sulfur dioxide and 8.169 mg of gaseous water are produced. Can the chemist determine the empirical formula for the compound? If so, determine the empirical formula. If not, what other information is needed, how you would collect in the laboratory and why the information is needed?

Answer 1

Since the compound releases CO2, H2O and SO2 on combustion,

the possible elements are C, H and S

Given, mass of SO2 = 13.905 mg.

Mass of H2O = 8.169 mg.

Mass of the sample = 12.65 mg.

To determine the emperical formula of the compound, it is needed the mass of carbon dioxide (CO2) produced. So that we can able calculate the % by masses of C, H and S from which we calculate the emperical formula of the compound.

Mass of carbon dioxde can be calcualted by passing CO2 gas over the known weight of KOH solution which absorbs CO2. The change in weight after the absorption will give the weight of CO2.