You’re probably familiar with the sour taste of acidic lemon juice and the slippery feel of alkaline (basic) soap. In fact, these characteristics were used to identify acids from bases long ago. Today, we understand much more about acidity and alkalinity, far beyond taste and feel. Acids are most simply defined as proton donors. They have a ph of below 7. They are substances that react with water to produce H3O+ (hydronium) ions (after all, H2O + one proton → H3O+ ). When you add an acid to water the water acts as a base, accepting protons from the acid. Bases are most simply defined as proton acceptors. They have a ph of above 7. They react with water to produce OH- (hydroxide) ions (H2O - one proton → OH-). When you add a base to water the water acts as an acid, donating protons to the base.1. Citric acid H3C6H5O7 is the substance that gives lemon juice and other citrus fruit juices a sour taste. How many grams of citric acid are present in 125mL of a 0.400M citric acid solution?