Answer:
the sun beams down on the pool and heats it up top to bottom the deeper the colder
The equation is balanced as follows
Mgcl2 +2AgNo3 -->2Agcl +Mg(No3)2
from equation above 1 mole of MgCl2 reacted with 2 moles of AgNo3 to form 2 moles of AgCl2 and 1 mole of Mg(NO3)2
when balancing equation the number of atom of element should be the same on each side of equation.