Mariana Trench and the Himalayan Mountains
Answer:
Classification of elements in groups provide us with a fixed pattern in which the elements change their properties periodically.
Explanation:
Answer:
0.7692 M ≅ 0.77 M.
Explanation:
- It is known that the no. of millimoles of a solution before dilution is equal to the no. of millimoles of the solution after the dilution.
<em>(MV) before dilution = (MV) after dilution.</em>
M before dilution = 2.0 M, V before dilution = 0.25 L.
M after dilution = ??? M, V after dilution = 0.25 L + 0.40 L = 0.65 L.
∴<em> M after dilution = (MV) before dilution/(V) after dilution</em> = (2.0 M)(0.25 L)/(0.65 L) =<em> 0.7692 M ≅ 0.77 M.</em>
Answer:
Br2 (l) + 2e- ---------> 2Br- (aq) E° = 1.08 V cathode
Cu2+ (aq) + e- --------->Cu+ (aq) E° = 0.15 V anode
Explanation:
We have to first state the fact that the reaction having the most positive reduction potential occurs at the cathode in any spontaneous electrochemical cell. The half reaction with the less positive electrode potential usually occurs at the anode.
The overall reaction equation is;
2Cu2+ (aq) + Br2 (l) ----->2Cu+ (aq) + 2Br- (aq)
E°cell= E°cathode - E°anode
E°cathode= 1.08 V
E°anode= 0.15V
E°cell = 1.08-0.15 = 0.93 V
But
∆G°= -nFE°cell
n= 2, F=96500C, E°cell= 0.93V
∆G° = -(2× 96500× 0.93)
∆G= -179490 J
But;
∆G = -RTlnK
R=8.314 JK-1
T= 25+273= 298K
Kc= the unknown
∆G° = -179490 J
Substituting values and making lnK the subject of the formula
lnK= ∆G/-RT
lnK= -( -179490/8.314 × 298)
lnK= 72.45
K= e^72.45
K= 2.91×10^31