Final answer:
Calcium (Ca2+) is the solute found in higher concentrations outside of the cell, not inside. This is in contrast to potassium (K+), which has higher concentrations inside the cell.
Step-by-step explanation:
The question asks which solute is found in higher concentration outside of the cell rather than inside. Given the information provided along with common biological principles, it can be deduced that calcium (Ca2+) ions are mostly found in higher concentrations in the extracellular fluid (ECF) as opposed to the intracellular fluid (ICF) where potassium (K+) ions are more prevalent. Additionally, ATP is known to power the sodium-potassium pump, which actively maintains high concentrations of potassium inside and high concentrations of sodium outside the cell.
Therefore, the solute found in higher concentration inside of the cell except for one listed is calcium, which is the correct answer to the question.