Potential energy given to each coulomb of charge

AI Thread Summary
The potential energy given to each coulomb of charge in a chemical cell involving zinc is calculated using the formula that incorporates energy released per mole, Avogadro's number, and the number of electrons transferred. With 300 kJ of energy released per mole of zinc and each zinc atom losing two electrons, the calculation yields a potential energy of 1.64 x 10^-20 kJ per electron. This translates to a potential difference where each coulomb of charge transferred in the reaction releases 1.64 x 10^-20 kJ of energy. The molar mass of zinc is mentioned but deemed irrelevant for this specific calculation. Thus, the discussion clarifies how to derive potential energy per coulomb in the context of zinc's electrochemical behavior.
benhorris
Messages
21
Reaction score
0
This is the info I am given...

e = 1.6 ´ 10–19 C
NA = 6.0 ´ 1023 particles / mole
Molar mass of zinc = 65.4 grams
In a chemical cell, the energy released by chemical attack on a metal, say zinc, as in many chemical reactions, is about 300 kJ per mole of metal attacked.

What is the potential energy given to each coulomb of charge (i.e. the potential difference)?
Remember that each zinc atom loses 2 electrons to become a Zn2+ ion. :confused:
 
Physics news on Phys.org
how many elecrons are lost in a mole of zinc if each zinc atom loses two?

How many electrons do you need to have a coulomb? (this number is the inverse of the charge of the electron).

A volt is a joule per coulomb.

molar mass is a red herring.
 


To calculate the potential energy given to each coulomb of charge, we can use the following formula:

Potential energy per coulomb = (Energy released per mole of metal / Avogadro's number) * (Molar mass of metal / Number of electrons transferred)

In this case, the energy released per mole of zinc is 300 kJ, the Avogadro's number is 6.0 x 10^23 particles/mole, the molar mass of zinc is 65.4 grams, and each zinc atom loses 2 electrons to become a Zn2+ ion.

Substituting these values into the formula, we get:

Potential energy per coulomb = (300 kJ/mol / 6.0 x 10^23 particles/mol) * (65.4 g/mol / 2 electrons)

= (5 x 10^-22 kJ/particle) * (32.7 g/electron)

= 1.64 x 10^-20 kJ/electron

Therefore, the potential energy given to each coulomb of charge, or the potential difference, is 1.64 x 10^-20 kJ/electron. This means that for every coulomb of charge transferred in the chemical reaction, 1.64 x 10^-20 kJ of energy is released.
 
Thread 'Collision of a bullet on a rod-string system: query'
In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
Thread 'A cylinder connected to a hanged mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top