The half reaction with the the greater SRP has a greater tendency to gain electrons is the definition of reduction potential when considering a pair of half cell reactions.This reduction potential is measured against hydrogen electrode which is standard electrode.
I believe you would just put a 2 in front of NH3 and keep the other ones as 1
Zn(s) + 2HCl(aq) = ZnCl₂(aq) + H₂(g)
zinc + hydrochloric acid = zinc chloride + hydrogen
Water levels tend to drop in dry weather because of evaporation. The hot temperatures will cause the water to achieve its gaseous state and go up into the atmosphere.
