What acids & bases can I find in the kitchen?
Acids like sulphuric acid give hydrogen ions away to water, while bases like sodium hydroxide take hydrogen ions. Despite the lab-associated images they call to mind, acids and bases are common items around the home.
You can find weak acids and bases in your own kitchen, all of which play an important role in cooking, cleaning and everyday life.
Vinegar is a solution of acetic acid, a weak acid with the molecular formula CH3COOH. Household vinegar usually has a pH of about 2.4. Vinegar not only makes a tasty addition to a variety of dishes and salad dressings, it can also be used for cleaning as well.
Baking soda or sodium bicarbonate is a weak base with the molecular formula NaHCO3; when it dissolves in water it dissociates into sodium ions and bicarbonate ions. Above 70 degrees Celsius, sodium bicarbonate breaks down to release CO2 gas, so it's often used in cooking as a leavening agent. Acetic acid and sodium bicarbonate neutralise each other when mixed in a reaction that releases copious bubbles of CO2 gas.
Citric acid is a weakly acidic compound that lends citrus fruits and lemonade their characteristic sour taste. Unlike acetic acid, it can donate more than one hydrogen ion to water.
Many (though not all) cleaning products are alkaline or basic. Many window cleaners, for example, contain ammonia, which is a weak base. Oven and drain cleaners sometimes contain a very strong base called sodium hydroxide.