Generally, when an acid and a base are added together in solution, a salt and water will form. This is known as an acid-base reaction. Therefore, the scientist may infer that she is working with an acid. (Acid + Base = H2O + Salt).
She can infer from the observation
that the unknown solution is acidic.
To add, acidic solutions<span> <span>are any </span></span>solution<span> <span>that has a higher concentration of hydrogen
ions than water; </span></span>solutions<span> <span>that have a lower concentration of hydrogen
ions than water are called basic or alkaline </span></span>solutions<span>.</span>