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.
Description and significance. Streptococcus mutans is a Gram-positive bacterium that lives in the mouth. It can thrive in temperature ranging from 18-40 degrees Celsius. The bacterium metabolizes different kinds of carbohydrates, creating an acidic environment in the mouth as a result of this process.