Predict which member of each pair produces the more acidic aqueous solution?
Al3 + or Ga3 + .
We’re asked to predict which ion: Al3+ or Ga3 produces the more acidic aqueous solution.
Recall that when comparing the acidity of cations in solution:
Since both cations have the same charge, we will compare their ionic radius using periodic trends to determine the smaller cation which produces a more acidic solution.
Recall that ionic radius is the size of an ion. The trend for ionic radius or size is as follows: it increases from right to left and down a period in the periodic table: