On the acid side:
H+ ions are correctly classified as acids because they donate protons and lower the pH of a solution.
Sour taste is also correctly classified as an acid property, as many acids have a sour taste.
However, pH = 5 is not wrong, but rather consistent with acidic properties.
On the base side:
OH- ions are correctly classified as bases because they accept protons and raise the pH of a solution.
Bitter taste is also correctly classified as a base property, as many bases have a bitter taste.
However, pH = 10 is not wrong, but rather consistent with basic properties.
H₂SO₄ is an acidic compound that can donate protons and lower the pH of a solution, so it is correctly classified as an acid. Ca(OH)₂ is a basic compound that can accept protons and raise the pH of a solution, so it is correctly classified as a base.
Sugar (C6H12O6) is a neutral compound that does not have acidic or basic properties, so it is not classified as either an acid or a base.