Question

For a 1.0x10^-2 m solution of NH4ClO4 (aq), arrange the species by their relative molar amounts in solution.

a) NH4+
b) ClO4-
c) H+
d) OH-

Answer 1

In a 1.0x10^-2 M solution of NH4ClO4, NH4+ and ClO4- will both be present in an equal concentration of 1.0x10^-2 M. H+ and OH- ions will be present in very low concentrations, with typical values around 1.0x10^-7 M from water's autoionization at 25°C.

Step-by-step explanation:

For a 1.0x10^-2 M solution of NH4ClO4 (aq), the species will be present in the solution in the following relative molar amounts:

1. NH4+ (ammonium) - since NH4ClO4 dissociates completely in water, it will be present in the same concentration as the original NH4ClO4, which is 1.0x10^-2 M.
2. ClO4- (perchlorate) - similar to NH4+, it will also be present at 1.0x10^-2 M.
3. H+ (proton) - the concentration of H+ in a neutral solution of water is very low, on the order of 1.0x10^-7 M due to autoionization of water.
4. OH- (hydroxide) - likewise, in pure water at 25°C, the concentration of OH- is also very low, around 1.0x10^-7 M, but in the presence of NH4+, which can act as a weak acid, the concentration might be slightly less due to slight acidification.

It is important to note that in this case, H+ and OH- ions are present in negligible amounts compared to NH4+ and ClO4- because NH4ClO4 is a salt that dissociates into its constituent ions in solution, and does not contribute significantly to H+ or OH- concentrations unless in an acidic or basic environment, respectively.