[Aufbau89]

Hello again 

Sorry but I've stumbled on more problems.  This time it is on electrolysis:

A solution containing Pt⁴⁺ is electrolyzed with a current of 4.00 A.  How long will it take to plate out 99% of the platinum in 0.50 L of a 0.010 M solution of Pt⁴⁼?

In my notes, I were given:
      1) Coulomb (C)
              1 mol electrons = 96, 485 C
      2) Joule (J) = energy
      3) ampere (A) = current = C/sec
      4) Watt (W) = power = J/sec
      5) voltage (V) = electrical potential = J/C

      * if I were given the mass in grams then I could easily use stoichometry to solve for the equivalence in seconds.  I'm not asking anyone to solve the entire problem, I just need to know what to do with the "99%", "0.50 L", and "o.010 M".  Is it possible to get the mass from these info?  Thanks alot.

[Borek]

Google Faraday's Law of electrolysis.

[xiankai]

I just need to know what to do with the "99%", "0.50 L", and "o.010 M".

99% of Pt --> in terms of moles

0.010M --> concentration of Pt⁴⁺ in solution

0.50L --> volume of solution

IMHO u should be trying to find the moles, not the mass

[Aufbau89]

I just need to know what to do with the "99%", "0.50 L", and "o.010 M".

99% of Pt --> in terms of moles

0.010M --> concentration of Pt⁴⁺ in solution

0.50L --> volume of solution

IMHO u should be trying to find the moles, not the mass

  Ah!!  Dang, I can't believe I forgot to think about that!  I could use the volume of .50L and the molarity of 0.010M to solve for the moles since M = moles/volume.  So I would do:

         0.010M = x moles/ .50 L
         therefore x = (.50L)(0.010M) = .005 moles Pt!

         then I would use that to solve for time by:

         .005 moles Pt   x   1 mol Pt⁴⁺ / 1 mol Pt   x   4(96, 485) C/ 4 mol e^-   x   1 sec / 4.00 C  =
                                                                                    120 secs
                 
             does that look right?