2. Subtract the mass of air from the mass of the empty stoppered flask to get the mass of flask and stopper without air. Mass of flask and stopper without air \( \qquad \) Calculation: \[ 156.763 \mathrm{~g}-272.6 \mathrm{~mL}= \] 3. Subtract the mass of flask and stopper without air from the mass of flask, stopper and CO 2 or CH 4 to get the mass of \( \mathbf{C O 2} \) or of CH 4 . Mass of CO2 \( \qquad \) Mass of CH 4 \( \qquad \) 40.837 g Calculation: \[ \begin{array}{l} \text { alculation: } \\ \left(\mathrm{CO}_{2}\right) \\ 156.96 \mathrm{~g}-115.8379 \end{array} \] \[ \begin{array}{l} (\mathrm{CH4}) \\ 156.7 \mathrm{lg}-115.837 \mathrm{~g} \end{array} \] \[ =41.1239 \] \[ =40.8739 \] 4. Convert temperature to Kelvins. \( \qquad \)

Did you know that the concept of subtracting masses to find the mass of gases in a flask is foundational in both chemistry and physics? This method not only helps in determining the exact mass of substances but also emphasizes the importance of precision in measurements, which is critical when conducting experiments. Kicking it up a notch, this technique lays the groundwork for understanding gas laws and stoichiometry, where these calculations become essential in predicting reactions and behaviors of gases under various conditions! In practical terms, mastering these calculations can have real-world applications, such as in environmental science, where you might measure the mass of carbon emissions in a lab setting or when developing new energy sources. For instance, knowing the mass of gases helps scientists find out how much CO2 is released during various combustion processes or how methane affects global warming. So whether you're brewing up some experimental science in the lab or busy calculating emissions for a greener planet, these skills will surely come in handy!