pH Calculation Practice

pH Calculation Practice

Interactive Practice

Objective

Relate the acid-base strength and the hydrogen and hydroxide concentration to the pH of a given solution.

Poll

How confident are you in your ability to perform pH calculations?

• Very confident

• Somewhat confident

• Barelty confident

• Not confient at all

Multiple Choice

What is the pH of a solution with a hydrogen ion concentration of 1x10^-4

• 3

• 10

• 4

• 14

Review

If given a concentration with a 1x10^x, take the absolute value of the exponent as the value of the pH.

Multiple Choice

What is the pH for a solution with the following hydrogen ion concentration: 1x10^-10?

• 10

• 4

• 3

• 14

Find the pOH from pH

Multiple Choice

If the pH of a solution is 4.0, what is the pOH?

• 4.0

• 10.0

• 1.0 x 10 ^-4

• cannot be determined from the information

Finding the pOH from pH

• The POGIL activity introduced you to the K_w value. (1.0x10^-14)

• If you take the negative log of K_w you get an answer of 14.

• For this reason, pH + pOH must equal 14.

• Use this relationship to determine the pOH value.

Multiple Choice

What is the pOH for the solution if the pH of the solution is 11?

• 11

• 3

• 14

• 1.0x10^-7

Finding the [H⁺] from the pH

Multiple Choice

The pH of a solution is 8.43. What is the [H₃O⁺]concentration?

• 3.7 x 10 ^-9

• 1.0 x 10^-8.43

• 2.7 x 10^-6

• 1.0 x 10^-14

Find the [H⁺] from pH

• We use the negative Log function to find the pH.

• So if we want to go the opposite direction, we must use the inverse.

Calculator Use for inverse Log

• If using a TI-30 or 84, Use the 2nd function LOG button

• If using the google, click the "INV" button then choose 10^x from there.

Multiple Choice

What is the [H₃O⁺] for a solution with a pH of 3.25?

• 5.62x10^-4

• 1778.28

• 5.62

• 1.79

Finding the [OH-] from pOH

Multiple Choice

If a solution has a pOH of 3.7 the [OH-] of the solution is

• 5.0 x 10^-11

• 2.0 x 10^-4

• 10.3

• 14

Finding the [OH^-] from pOH

• Similar to finding the hydrogen ion concentration from pH

• Use the inverse Log function, make sure that it is the 10^-pOH

Multiple Choice

if a solution has a pOH of 5.2 the [OH-] of the solution is

• 6 x 10 ^-6 M

• 6.3 x 10 ^-6 M

• 1.58 x 10^-5 M

• 2 x 10^-5 M

Finding the pH from [OH^-]

Multiple Choice

Find the pH of a solution with [OH-] = 8.41 x 10^-4. (Hint: find pOH, then pH)

• 3.08

• 10.92

• 9.88

• 11.23

Finding the pH from [OH^-]

• Find the pOH using pOH= - log[OH^-]

• Subtract the pOH from 14

Multiple Choice

What is the pH if the [OH^-] is 3.13x10^-9?

• 8.50

• 5.5

• 19.5

• 3.19x10^-6

Poll

After practicing, How confident are you in completing pH calculations?

• Very Confident

• Somewhat confident

• Barely Confident

• Not confident at all

Challenge Round

Ready to check

Multiple Choice

A solution of KOH is 2.5 x 10^-5 M. What is the [H⁺] concentration? (Hint: Find pOH, then pH, then [H⁺].)

• 4.60

• 9.40

• 3.98 x 10^-10

• 1.0 x 10^-4.60

Multiple Choice

What is the [OH-] if the pH is 4.9?

• 4.9 x 10^-10 M

• 1.0 x 10^-4 M

• 1.25 x 10^-5 M

• 7.94 x 10^-10 M