Can someone direct me on the question below? I am not sure how to work this problem. Thank you.
Chambers A and B are separated by a membrane. Chamber A contains 15.7 M KNO3 and chamber B contains 10.98 M KNO3. If K+ is in equilibrium across the membrane, what is the electrical (potential) difference (Resting membrane potential)? Which side is electrically positive?
To find the electrical potential difference (resting membrane potential) and determine which side is electrically positive, we need to use the Nernst equation. This equation allows us to calculate the potential difference by considering the concentration gradient of ions across the membrane.
The Nernst equation is as follows:
E = (RT/zF) * ln([K+]outside/[K+]inside)
Where:
E = electrical potential difference (in volts)
R = gas constant (8.314 J/mol*K)
T = temperature in Kelvin
z = valence of the ion (in this case, K+ has a charge of +1)
F = Faraday's constant (96485 C/mol)
[K+]outside = concentration of K+ outside the membrane
[K+]inside = concentration of K+ inside the membrane
Given in the problem:
[K+]outside = 10.98 M (chamber B)
[K+]inside = 15.7 M (chamber A)
To solve the problem, we can plug in these values into the Nernst equation and calculate the electrical potential difference.
Resting membrane potential (E) = (RT/zF) * ln([K+]outside/[K+]inside)
= (8.314 J/mol*K) * (298.15 K) / (1 * 96485 C/mol) * ln(10.98 / 15.7)
By substituting the known values into the equation, we can evaluate the natural logarithm, and then calculate the expression inside the parentheses.
Now, to determine which side is electrically positive, we need to compare the calculated electrical potential difference (E) with zero. If E is positive, then the side with a higher concentration of K+ (chamber B) is electrically positive. If E is negative, then the side with a lower concentration of K+ (chamber A) is electrically positive.
By following these steps and performing the calculations, you should be able to find the electrical potential difference and determine which side is electrically positive.