True or false. A titration determines the concentration of only an acid by adding a solution of a known volume and concentration.

False, it's not only for acids. I've put alkalis and phenolphthalein (an indicator that goes colourless in the presence of acid) into the beaker and had an acid in the burette.

What a titration actually does is calculates the exact amount of one solution that reacts with a different one.

Whatever happens, you need to know the substances are pure, and the concentration/volume of the substance in the burette.