1. Will MnO4- oxidize Cr+3 to Cr2O7 in acidic solution? Explain your answer.
Reduction Potentials E°
Mn+2 + 2e- Mn(s) -1.18
Cr+2 + 2e- Cr(s) -0.91
Cr+3 + e- Cr+2 -0.41
MnO2 + 4H+ + 2e- Mn+2 + 2H2O 1.23
Cr2O7-2 + 14H+ + 6e- 2Cr+3 + 7H2O 1.33
MnO4- + 8H+ + 5e- Mn+2 + 4H2O 1.51
2. Calculate the number of moles of CuBr which will dissolve in 0.010M HBr.
Ksp for CuBr is 5.3x10-9.
If someone could help me out it would be great. I've been at these for a while and I can't seem to get the correct answer that I have in my book.
2007-08-19 09:11:14 · 4 answers · asked by Sarah G 1 in Science & Mathematics ➔ Chemistry
The answer lies in the last two entries in your list of electrode potentials. The fact that, for (MnO4)-, on the left of the equation, the voltage is 1.51, and for Cr3+, just above it, on the right of the equation, it is only 1.33, means that the bottom one can force the next one up backwards.
Very simply, the answer is yes.
For the Ksp question, you haven't said what volume of HBr. 0.01 x [CuBr] must equal Ksp, so you can work out the maximium molarity of CuBr, and from the the moles.
2007-08-19 10:32:05 · answer #1 · answered by Gervald F 7 · 1⤊ 0⤋
1)higher the reduction potential , higher is the oxidinzing capacity..
and so Mn wont oxidize Cr as it is weaker than Cr....
2007-08-19 16:26:49 · answer #2 · answered by rex.speaks 1 · 0⤊ 1⤋
Gervald is correct -permanganate is one of the strongest oxidisers around.
2007-08-19 17:58:04 · answer #3 · answered by Aurium 6 · 0⤊ 0⤋
Halt! Cease you "equation inquest" immediately!
This is the formula for opening up the Gates of Hell!
Do not proceed...!
"Hell" is not something you want to suddenly appear in your chemistry beaker...or during a mid-term...!!!
You have been warned...
2007-08-19 16:20:35 · answer #4 · answered by Anonymous · 0⤊ 2⤋