the activity series of metals is:

Au < Ag < Cu < Sn < Cd < Zn < Al < Mg < Na < Cs
which reaction below occutrs spontaneously upong mixing the reageant shown?
a) Sn(s) + Al3+ (aq)-> sn2+(aq) + al(s)
b) sn(s) + zn 2+ (aq) -> sn 2+ (aq) +zn (s)
c) zn (s) + au 3+ (aq) -> zn 2+ (aq) + au (s)
d) ag(s) + mg 2+ (aq) -> ag+ (aq) + mg (s)
e) ag(s) + mn2+ (aq) -> ag+(aq) + mn(s)

To determine which reaction occurs spontaneously, we need to compare the positions of the metals involved in the activity series. The higher the position of a metal in the activity series, the more reactive it is. A metal higher in the series can displace a metal lower in the series in an aqueous solution, leading to a spontaneous reaction.

Let's analyze each option:

a) Sn(s) + Al3+(aq) -> Sn2+(aq) + Al(s)
Tin (Sn) is below aluminum (Al) in the activity series. Therefore, it is less reactive than aluminum, and this reaction will not occur spontaneously.

b) Sn(s) + Zn2+(aq) -> Sn2+(aq) + Zn(s)
Tin (Sn) is above zinc (Zn) in the activity series. Therefore, it is more reactive than zinc, and this reaction will occur spontaneously.

c) Zn(s) + Au3+(aq) -> Zn2+(aq) + Au(s)
Zinc (Zn) is above gold (Au) in the activity series. Therefore, it is more reactive than gold, and this reaction will occur spontaneously.

d) Ag(s) + Mg2+(aq) -> Ag+(aq) + Mg(s)
Silver (Ag) is below magnesium (Mg) in the activity series. Therefore, it is less reactive than magnesium, and this reaction will not occur spontaneously.

e) Ag(s) + Mn2+(aq) -> Ag+(aq) + Mn(s)
Silver (Ag) is below manganese (Mn) in the activity series. Therefore, it is less reactive than manganese, and this reaction will not occur spontaneously.

So, the reactions that occur spontaneously upon mixing the reagents are:
- Reaction b) Sn(s) + Zn2+(aq) -> Sn2+(aq) + Zn(s)
- Reaction c) Zn(s) + Au3+(aq) -> Zn2+(aq) + Au(s)

Option d) and e) do not occur spontaneously.