[Co(NH₃)₅Br]²⁺
Ligands and charges on them,
5 × NH₃ = 5 × 0 = 0
1 × Br⁻¹ = 1 × -1 = -1
Charge on sphere = +2
So, putting values in equation,
Co + (0)₅ - 1 = +2
Co + 0 - 1 = +2
Co - 1 = +2
Co = +2 + 1
Co = +3
Result:
Oxidation state of Co in [Co(NH₃)₅Br]²⁺ is +3.
Answer:
1.39
Explanation:
[Hg2Cl2]= 1M
[H^+] = ????
E°cell= 0.35V
E= 0.268 V
Therefore E for the reaction must -0.082 V
n= 2 moles of electrons
From Nernst Equation:
E= E°cell- 0.0592/n log [Red]/[Ox]
0.0268= 0.35- 0.0592/2 log 1/[Ox]^2
-0.082= -0.0296 log 1/[Ox]^2
log 1/[Ox]^2= 0.082/0.0296
log 1/[Ox]^2= 2.77
1/[Ox]^2=Antilog (2.77)
[Ox]^2=1.698×10^-3
[Ox] = 0.0412 M
But pH= -log [H^+]= -log(0.0412)= 1.385
When air pressure is low it is Cold