It’s your first day on the job, working as an analytical chemist for Exxon-Mobil! The lead petroleum engineer comes to you, saying that they had an unexpected layer in their fractional distillation and would like you to investigate the compound. They give you a purified, 100g sample of this unknown hydrocarbon (CxHy) to analyze to determine the chemical makeup. You decide that you should burn (combust!) the mystery compound to determine its chemical formula through quantitative analysis. After using enough oxygen to completely combust the entire sample, you measure the resulting products.

Doing so yields 343.356 g of a colorless, relatively inert gas and 56.22 g of a clear gas which quickly condenses to a liquid at room temperature. You also determine the molar mass of the compound to be 128.17 g/mol.

Please list the steps you would use to solve the problem, and give your boss a molecular formula of the unknown compound.

Some tips:
Review what a combustion reaction is! What are the products?
Identify what the two products are! Can you calculate their molar masses?
Make sure to compare ratios of the elements themselves!
Once you have the empirical formula, how can you find out the molecular formula?