Example: Calculate the pH of a buffer solution that initially consists of 0.0400 moles of ammonia and 0.0250 moles of ammonium ion, after 20.0 mL of 0.75 M NaOH has been added to the buffer. Ka for ammonium ion is 5.6 x 10 -10.
There are two types of bacteria. Aerobic bacteria live with oxygen, love the company of food particles in the mouth and feed on sugar. Anaerobic bacteria exist without oxygen and feed off dead skin cells and other bacteria.
Bacteria that live in your mouth thrive on the sugars and starches in the food you eat. These bacteria form a sticky plaque that clings to the surface of your teeth. Acids produced by the bacteria in plaque can eat through the hard, white coating on the outside of your teeth (enamel), creating a cavity.