Answer:
Surely with water
Ok, but how?
There are many Hydrogen Bond between H2O moleculs and london bonds. When fishes take water with their gill,they are broke london bonds. And they can take their needs, Oxygen. Only this.
Good luck :D
The first half reaction is:
Sn+ -> Sn2+
You add 1 electron on the right side:
Sn+ -> Sn2+ + 1e-
The second half reacation is:
Ag+ -> Ag
You add 1 electron to the left side:
Ag+ + 1e- -> Ag
Then, you combine both reactions to get the balanced overall reaction since both half reactions have 1 electrons on the right and left side, respectively. You get:
Sn+ + Ag+ -> Sn2+ + Ag