Voltage Vs Pressure: Ideal Gases- not so ideal?

In summary: Overall, experimental data and potentiostatic control can provide valuable information on the relationship between pressure and voltage in high pressure electrolysis experiments. In summary, under pressures greater than 100 bar, the Nernst equation is not applicable due to non-ideal gas behavior. To determine the relationship between pressure and voltage in a high pressure electrolysis system, potentiostatic control can be used to measure the potential difference between electrodes. Additionally, the overpotential of the electrodes must be taken into account in order to accurately interpret experimental data.
  • #1
kormu
1
0
Hi, I was wondering what effects pressures (>100bar) would have on half-cell reactions. Normally, I'd use the Nernst Equation, but under immense pressures the value "R" is no longer ideal (pun intentional). The electrical pressure (voltage) goes up because (I would assume because) the number of joules goes up, since the pressure is increased there's more energy at a given temperature (but I have no idea how much)... plus no gas is ideal, especially at high pressures.
I'm designing an "amateur" experiment doing high pressure electrolysis. If anyone knows of any papers on this subject, or can point me in a new direction- that would be very kind of you. I've already asked a few professors (one chemistry, two physics) and we got no where; I looked on google scholar and I can't find anything useful. Approximations won't be very helpful, experimental data would be most helpful (since I hear overpotentials must be determined experimentally). It'd be neat to compare the different electrode efficiencies, but I'm mostly interested in the relationship between pressure and voltage for electrolysis (I hope its linear).
 
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  • #2
Under pressures higher than 100 bar, the Nernst equation is generally not applicable as it assumes ideal gas behavior. The ideal gas law states that pressure is proportional to the number of moles of a gas per unit volume and temperature, which is not valid under high pressures. Therefore, the electrical pressure (voltage) in a high pressure system will not necessarily follow the Nernst equation.The relationship between pressure and voltage in a high pressure electrolysis system can be determined experimentally using a technique called potentiostatic control. In this technique, the voltage is kept constant while the pressure is varied. This allows for the measurement of the potential difference between the two electrodes as a function of pressure, and can provide insight into the effect of pressure on the half-cell reactions.In addition, it is important to consider the overpotential of the electrodes when performing an electrolysis experiment at high pressures. The overpotential is the difference between the equilibrium potential of the reaction and the applied voltage, and is a measure of the energy losses due to side reactions and kinetic effects. Overpotentials must be determined experimentally, and therefore, any potential differences measured during the experiment should be corrected to account for the overpotential.
 

1. What is the relationship between voltage and pressure in ideal gases?

In ideal gases, the relationship between voltage and pressure is known as the Ideal Gas Law, which states that the product of the pressure and the volume of an ideal gas is directly proportional to the number of moles of gas, the temperature, and the ideal gas constant. This means that as the voltage increases, the pressure of the gas will also increase, assuming all other variables remain constant.

2. How is voltage related to the motion of gas particles?

Voltage is related to the motion of gas particles through the kinetic theory of gases. This theory states that gas particles are in constant, random motion and that this motion increases with an increase in temperature or a decrease in volume. As voltage increases, the temperature of the gas also increases, causing the gas particles to move faster and collide with each other more frequently, resulting in a higher pressure.

3. Can the Ideal Gas Law be applied to all gases?

The Ideal Gas Law can only be applied to ideal gases, which are hypothetical gases that follow certain assumptions, such as having no intermolecular forces and occupying no volume. Real gases, on the other hand, deviate from these assumptions and therefore do not strictly follow the Ideal Gas Law. However, at low pressures and high temperatures, most gases behave similarly to an ideal gas and the Ideal Gas Law can be used as an approximation.

4. How does non-ideal behavior affect the relationship between voltage and pressure in gases?

Non-ideal behavior, such as intermolecular forces and volume occupancy, can affect the relationship between voltage and pressure in gases. These factors can cause deviations from the Ideal Gas Law and result in a non-linear relationship between voltage and pressure. In non-ideal gases, the relationship between voltage and pressure may also vary depending on the temperature and the gas’s composition.

5. What are some practical applications of understanding the relationship between voltage and pressure in gases?

The relationship between voltage and pressure in gases has many practical applications. For example, it is essential in understanding the behavior of gases in various industrial processes, such as in the production of energy and chemicals. It is also crucial in the design and operation of gas-based systems, such as gas turbines and refrigeration systems. Additionally, understanding this relationship is crucial in fields like chemistry and physics, where gases are used in experiments and analyses.

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