Ionization Energy in Electron Volts

AI Thread Summary
To ionize one mole of molecular hydrogen (H2), approximately 10 eV of energy is required per hydrogen atom, totaling 20 eV for the two atoms in H2. Converting this energy to joules involves multiplying by Avogadro's number, which is about 6 × 10^23. The calculation involves using the conversion factor of 1 eV = 1.6 × 10^-19 J. Therefore, the total energy needed in joules is 20 eV multiplied by 1.6 × 10^-19 J/eV, then multiplied by 6 × 10^23. The final result provides the energy required to ionize all hydrogen atoms in one mole of H2.
mhrokosz
Messages
3
Reaction score
0

Homework Statement



(10.) It requires roughly 10 eV to ionize one hydrogen atom. How much energy (in joules) are needed to ionize all the hydrogen atoms in one mole of molecular hydrogen (H2)? [Recall: 1 eV = 1.6 × 10−19 J and Avogadro’s constant is about 6 × 1023.]


Homework Equations



I don't know what equation to use that would include Avogadro's number...this is probably very elementary, I apologize.

The Attempt at a Solution

 
Physics news on Phys.org
Don't look for some equation. Think it out.
 
2 atoms;
(1.6 × 10−19 J) x 20? that simple?
 
How many hydrogen molecules in a mole?
 
Ahhhh.

(A's# x 2 H molecules)(20 eV)(1.6x10^-19)
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging 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