Sample Calculation of the Charge on the Electron

 

In an experiment,  a student obtained the following data.  Use it to calculate the charge on the electron.

 

“off-scale” volume (V in Fig. 2)

5.11 mL

Buret reading after electrolysis

48.00 mL

Patm

765.8 Torr

Height of solution column (h in Fig. 2)

52.8 cm

Temperature of H2

22.0o C

Electrolysis time

23 min

Average current

37.1 milliampere (mA)

Vapor pressure of water at 22oC

19.83 Torr

 

Solution

 

1.       Calculate the pressure in kilopascals (kPa)

 

1 atm = 1.01325x105 Pa

 

 

    

 

 

 

 

 

  

 

  1. Calcuate the moles of H2

 

 

 

 

 

3. Calculate the moles of electrons

 

   

 

4.  Calculate the charge on the electron