2 Worksheet Acids and Bases PDF

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Worksheet Worksheet:: Acids and Bases Complet Complete e the below document and submit to D2L by the defined due date. Responses must be typed and document saved as pdf p prior rior to submitting.

1) What is meant by the term “ionization is incomplete”? Weak acids and bases are unable to fully ionize when placed in an aqueous solution. This is because neither weak bases or weak acids have a strong tendency to transfer H + ions which keeps the reaction in an incomplete state.

2) What is pH of 0.0054 M HCl? pH = 2.27 3) What is pH of 0.0054 M NaOH? pH = 11.73 4) What is pH of 0.0054 M Sr(OH)2? Note: what does the subscript 2 represent? pH = 12.03 5) What is the pH of 2.3 M HNO3? pH = -0.36 6) If you are given the pH of a solution, what do you need to do to determine the [H 3O+]? [H3O+] = 10-pH

7) The concentration of calcium hydroxide in a saturated solution is 0.025 M. What is the pH of the solution? Is it acidic or basic? Note: be sure to really think about the empirical formula for calcium hydroxide. pH = 12.40, this solution is basic 8) The concentration of OH- ions in a sample of seawater is 5.0 x 10-6 M. a. Calculate the [H3O+] and classify the solution as neutral, acidic, or basic. [H3O+] = 2.02 x 10-9 this solution is basic. b. Calculate the pOH of the above solution and indicate whether a small or large pOH value is indicative of a basic solution. pOH = 5.3, smaller pOH values are indicative of a basic solution.

9) Calculate the pH of a solution that is 1.0 x 10-8 M in HCl. Does this answer make sense? What might you need to consider when determining the pH of very dilute acids. pH = 6.00, this solution makes sense however you have to take into consideration the fact that strong acids will completely ionize.

10) At 10.0⁰C, the pH of pure water is 7.27 Note: in pure water [H3O+] = [OH-] a. Calculate the Kw for pure water at this temperature? Kw = 2.88 x 10-15 b. Is the sample acidic, basic or neutral? This sample is acidic. 11) HA represents a generic weak acid. Write the equilibrium reaction that results when it reacts with water. Write the mass action equilibrium expression that defines this reaction, Ka = … HA

+

H3O+

H2O

+

:A

12) : B represents a generic weak base. Write the equilibrium reaction that results when it reacts with water. Write the mass action equilibrium expression that defines this reaction, Kb = … :B

+

H2O

HB

+

OH-

13) Write the formula for each of the following: a. the conjugate base of NH 4+ NH3 b. the conjugate base of H3PO4 H2PO4c. the conjugate acid of CO32− HCO3d. the conjugate acid of H 2O H3O+

e. the conjugate base of HSO4− SO42f. the conjugate base of H 2PO4− HPO42g. the conjugate base of HC6H3O52C6H3O53h. the conjugate acid of C 2H6NH HC2H6NH+

14) Provide two things that distinguish a strong acid from a weak acid. A strong acid will ionize completely and the strong acid has a higher K a.

15) The following is a list of weak acids and their Ka values: HOCl hypochlorous acid 3.5 x 10−8 H2S hydrogen sulfide 1.1 x 10−7 HCN hydrocyanic acid 4.0 x 10−10 HNO2 nitrous acid 4.5 x 10−4

a. Which acid given above is the strongest? Explain your choice.

Nitrous Acid is the strongest because a larger Ka means a stringer acid. b. Write the Ka mass action expression for the strongest acid. Ka =

[𝐻30+][𝑁𝑂2−] [𝐻𝑁𝑂2]

c. Which acid has the strongest conjugate base? Explain your choice. Hydrocyanic acid has the strongest conjugate base because it is the weakest acid and weak acids produce a stronger conjugate base. 16) pKa and pKb will be used in chapter 17 to calculate the pH of certain solutions like Ka, its value can be used to show the relative strength of an acid or base. Write a general statement that states the relationship between pK a or pKb and the relative strength of the acid or base. A lower pKa or pKb indicates a stronger acid or base....