Questions: Suppose when you inverted the eudiometer, a bubble of air became trapped inside it. Would this make your experimental value of R larger, smaller, or have no effect? Briefly explain your response.

Suppose when you inverted the eudiometer, a bubble of air became trapped inside it. Would this make your experimental value of R larger, smaller, or have no effect? Briefly explain your response.

Transcript text: 2) Suppose when you inverted the eudiometer, a bubble of air became trapped inside it. Would this make your experimental value of $R$ larger, smaller, or have no effect? Briefly explain your response.

Solution

Solution Steps

Step 1: Understanding the Eudiometer Experiment

In a typical eudiometer experiment, the gas collected is used to determine the ideal gas constant $ R $. The volume of gas, pressure, and temperature are measured to calculate $ R $ using the ideal gas law:

\[ PV = nRT \]

where $ P $ is the pressure, $ V $ is the volume, $ n $ is the number of moles, $ R $ is the ideal gas constant, and $ T $ is the temperature.

Step 2: Analyzing the Effect of a Trapped Air Bubble

If a bubble of air is trapped inside the eudiometer, it will add to the total volume of gas measured. However, this trapped air does not contribute to the chemical reaction or the number of moles of gas produced by the reaction. Therefore, the volume $ V $ used in the calculation of $ R $ will be larger than it should be.

Step 3: Impact on the Experimental Value of $ R $

Since the volume $ V $ is overestimated due to the trapped air bubble, the calculated value of $ R $ will be larger than the true value. This is because the formula for $ R $ is rearranged as:

\[ R = \frac{PV}{nT} \]

An overestimated $ V $ leads to an overestimated $ R $.