Which reactants would lead to a spontaneous reaction?
mn2+ and al
mn and al3+
al and mn
mn2+ and al3+

The reactants that would lead to a spontaneous reaction are Mn2+ and Al3+. Al and Mn  are not because they are stable reactants. Mn and Al3+ are not because Mn is stable. Mn2+ and Al are not because Al is stable.

the ideal gas law equation is as follows

pv = nrt

where p - pressure

v - volume

n - number of moles

r - universal gas constant

t - temperature

so if the pressure, volume and temperature are already known

we are left with n and r

since r is the universal gas constant that has a known fixed value then r too is known

so we are left with 'n'

once we know temperature volume and pressure

we can find the number of moles of gas present using the ideal gas law equation

this is not my own answer, this is an answer for the same question by the user blahblahmali. i do not claim ownership of this account.

he would use the colour black