Evaluate the next few problems with your calculator, using the "change of base" formula.
There is an example to the right.
Question 20
20.
Use the change of base formula to evaluate. Round to the hundredths place (2 decimal places).
Question 21
21.
Use the change of base formula to evaluate. Round to the hundredths place (2 decimal places).
Question 22
22.
Use the change of base formula to evaluate. Round to the hundredths place (2 decimal places).
Question 23
23.
Use the change of base formula to evaluate. Round to the hundredths place (2 decimal places).
Question 24
24.
The acidity level, pH, of a liquid is given by the formula:
where h+ is the concentration of hydrogen ions in the water, measured in moles per liter.
Elijah decides to have a pool party for his birthday party. Before the party, the pool had a pH level of 4.8. After everyone went swimming, they measured the pool, and it had a concentration of h+ ions of .00000042 moles per liter.
Find the pH level of the pool AFTER the party and determine how much higher the pH level is now than before the party.
