**Category:** Organic Chemistry  
**Subtype:** Combustion Reactions and Stoichiometry  
**Problem Description:** The problem involves the complete combustion of a mixture of organic compounds (methyl propionate, methyl acetate, and two open-chain hydrocarbons) to determine the mass of the mixture (m). It provides information about the amount of oxygen consumed during combustion and the mass of water produced. Additionally, it involves a reaction with excess sodium hydroxide (NaOH) to find the amount of NaOH that reacted. The goal is to calculate the value of m.