Chem 20 Unit C Quiz 3 Review

Knowledge

100

If you added chlorophenol red to a solution and it turned red, what can you assume the pH of the solution to be?

Above 6.8 

6.8-14

200

Fill in the blank

pH is realated to the concentration of ____________ ions.

Hydronium

300

Name two properties of strong acids and two of strong bases.

High conductivity, low or high pH, dissociates/ionizes almost completely, lots of [H₃O⁺] or [OH^-]

400

Name two properties of weak acids and two for weak bases.

Low conductivity, higher/lower pH closer to 7, reacts partially with water, few [H₃O⁺]/[OH^-] in solution

500

What is the difference between the Arrhenius theory of acids and base and the modified Arrhenius theory of acids and base. 

Arrhenius: Acid/Base ioninizes/dissociates in water to form [H]/[OH^-]

Modified Arrhenius: Acid/Base reacts with water to produce [H₃O⁺]/[OH^-]

Acids / Bases

100

A solution with a pH of 6.5 is considered to be a/an?

A) Acid

B) Base

C) Neutral

A) Acid

200

Name two differences between an acid and a base.

Answers may vary

300

Using the modified Arrhenius theory, demonstrate why H₂PO₄^- can be both a base and an acid.

H₂PO₄^- + H₂O -> HPO₄^2- + H₃O⁺

H₂PO₄^- + H₂O -> H₃PO₄ + OH^-

On the test, do not forget the states!

400

When you dipped a litmus paper inside a solution of sodium sulphate, it changed from red to blue. Use the modified Arrenhenius theory to demonstrate why this is. 

Sodium sulphate dissociates to Na⁺ and SO₄^2-

SO₄^2- + H₂O -> HSO₄^- + OH^-

Since the sulphate reacts with water to form OH^-, by the modified Arrenhius theory, it acts as a base.

On the test, do not forget the states!

500

A 2.00L solution of hydrochloric acid has a pH of 1.251. Calculate the mass of hydrogen chloride required to make this solution.

Do on board: 4.08g

pH / pOH

100

If a solution has a pH of 4.00, what is the pOH?

10.00

200

If one solution has a pH or 4.2 and another solution has a pH of 8.2, how much weaker is the hydronium ion concentration?

10⁴ = 10,000 times weaker

300

In a basic solution, is the pOH higher than or lower than the pH?

pOH is lower(test it out if you want)

400

If a solution has an hydronium concentration of 1.45 x 10^-4, what is the pOH of this solution?

POH = 10.161

500

If you take 20 mL of a 5.00 mol/L solution of KOH(aq) and dilute it to 2.00L. What will be the pH of this solution?

pH = 12.70

Concentration

100

If the pH of a solution is 5.67, what is the hydronium ion concentration?

2.1 x 10^-6 mol/L

200

If the [OH^-] > [H₃O⁺] in a solution, then the solution is considered to be more?

A) Acidic

B) Basic

B) Basic

300

If the concentration of hydrogen bromide is 0.0123 mol/L, then the pOH of this solution would be?

12.090

400

YOU LOSE!

- 400 points for whoever selected this question!

500

Determine the concentration of Ca(OH)₂ that would be required in order to make a solution with a pH of 12.598

0.0198 mol/L