pH Scale, pH of Salts and pH of weak acids_bases - March 6th_7th (Workshop 7)

Correct Chapter 17 Algorithmic Question 35 Part A Calculate the pH for an aqueous acetic acid solution that contains 2.15 × 10 -3 M hydronium ion. ANSWER: Correct Chapter 17 Multiple Choice Question 14 Part A Which of the following is TRUE? ANSWER: acidic, 2.41 × 10 -11 M acidic, 2.41 × 10 -12 M basic, 2.41 × 10 -12 M acidic, 4.15 × 10 -3 M basic, 2.41 × 10 -11 M 4.65 × 10 -12 2.15 × 10 -3 2.668 11.33 12.22 A basic solution does not contain H 3 O + An acidic solution has [H 3 O + ] > [OH - ] An neutral solution does not contain any H 3 O + or OH - A neutral solution contains [H 2 O] = [H 3 O + ] None of the above are true.

Part A Define . What range is considered acidic? Basic? Neutral? Match the items in the left column to the appropriate blanks in the sentences on the right. ANSWER: Exercise 17.49 - Enhanced - with Feedback MISSED THIS? Read Section 17.5. You can click on the Review link to access the section in your eText. Calculate in each aqueous solution at 25 . Part A Express the molarity to two significant figures. ANSWER: Part B Express the molarity to two significant figures. ANSWER: Reset Help 7 14 0 acidic basic neutral is defined as . A solution that is has . A solution that is has , and a solution that is has . = =

The scale used for measuring the acidity or basicity of a solution is known as the pH scale . Typically you will see values ranging from 0 to 14, however it is possible to produce highly acidic solutions with a lower pH or a highly basic solution with a higher pH. A neutral solution has an equivalent concentration of hydronium and hydroxide ions, which has a of 7 at 25 . A less than 7 indicates that a solution is an acid, and a greater than 7 indicates that a solution is a base. Click on the image below to explore this simulation , which demonstrates the scale. The of the solution is related to the ion concentration by the equation When you click the simulation link, you may be asked whether to run, open, or save the file. Choose to run or open it. In this simulation, allowing you to produce solutions at at 25 , you should see three modes: Macro , Micro , and Custom . In Macro and Micro , you are provided with a calibrated beaker along with an inlet and an outlet tap. You can choose different solutions from the dropdown list above the beaker in the simulation. In Macro mode, the scale displayed on the left side of the beaker indicates the of the solution. In Micro mode, the graphic to the left gives the concentration, or number of moles, of , , and . Part A In the simulation, select the Macro mode. Then choose each of the following solutions from the dropdown list provided in the upper left corner. The beaker will automatically fill up to the 0.50 mark with the solution, and the scale displayed on the left side of the beaker will indicate the of the solution at 25 . Classify the following solutions as acids, bases, or neutral based on their values as shown in the simulation. Drag the appropriate items to their respective bins. You did not open hints for this part. ANSWER:

Chapter 17 Multiple Choice Question 54 Part A Determine the pH of a 0.033 M HNO 3 solution. ANSWER: Correct Chapter 17 Reading Question 5 Part A What is the [H 3 O + ] of a 0.100 M solution of HClO? HClO has a K a = 2.9 × 10 −8 ? Hint 1. How to approach the problem This is similar to all equilibrium calculations. Set up an ICE table to describe initial concentrations, changes in concentration, and equilibrium concentrations. Then use the K a expression to solve for [H 3 O + ]. ANSWER: Correct Exercise 17.18 When calculating for weak acid solutions, we can often use the is small approximation. 2.96 6.26 2.49 1.48 12.52 2.9 × 10 −9 M 5.4 × 10 −5 M 1.7 × 10 −4 M 0.100 M

Exercise 17.76 - Enhanced - with Expanded Hints MISSED THIS? Watch KCV: Finding the [H3O+] and pH of Strong and Weak Acid Solutions , IWE: Finding the Percent Ionization of a Weak Acid ; Read Section 17.6. You can click on the Review link to access the section in your eText. Part A Determine the percent ionization of a 0.250 solution of benzoic acid ( ). Express the percentage to two significant figures. You did not open hints for this part. ANSWER: Exercise 17.80 - Enhanced - with Feedback and Hints MISSED THIS? Watch KCV: Finding the [H3O+] and pH of Strong and Weak Acid Solutions , IWE: Finding the Percent Ionization of a Weak Acid ; Read Section 17.6. You can click on the Review link to access the section in your eText. A 0.090 solution of a monoprotic acid has a percent dissociation of 0.60 . Part A Determine the acid ionization constant for the acid. Express your answer using two significant figures. You did not open hints for this part. ANSWER: Exercise 17.84 - Enhanced - with Feedback MISSED THIS? Read Section 17.6. You can click on the Review link to access the section in your eText. Find the pH of each mixture of acids. Part A 0.080 in and 0.180 in Express your answer to two decimal places. ANSWER: Part B 0.025 in and 0.020 in = =

Correct Chapter 17 Algorithmic Question 52 Part A Determine the [OH - ] ion concentration in a 0.235 M NaOH solution. ANSWER: Correct Chapter 17 Algorithmic Question 55 Part A Determine the pH of a 0.116 M Ba(OH) 2 solution at 25°C. ANSWER: CH 2 CH 2 NaOH N 2 NH(CH 3 ) 2 None of the above is a weak base. 0.235 M 4.25 × 10 -14 M 2.13 × 10 -14 M 0.118 M 0.470 M 13.06 0.936 12.13 0.634 13.365

Correct Exercise 17.96 - Enhanced - with Feedback MISSED THIS? Watch IWE: Finding the [OH−] and pH of a Weak Base Solution ; Read Section 17.7. You can click on the Review link to access the section in your eText. Amphetamine is a weak base with a of 4.2. Part A Calculate the of a solution containing an amphetamine concentration of 230 . Express your answer to two decimal places. ANSWER: Exercise 17.140 The AIDS drug zalcitabine ( , also known as ddC) is a weak base with the structure shown below and a of 9.8. Part A What percentage of the base is protonated in an aqueous zalcitabine solution containing 570 ? Express your answer using two significant figures. ANSWER: Exercise 17.145 Write net ionic equations for the reactions that take place when aqueous solutions of the following substances are mixed. Part A sodium cyanide and nitric acid Express your answer as a chemical equation. Identify all of the phases in your answer. Enter noreaction if there is no reaction. ANSWER: Part B ammonium chloride and sodium hydroxide Express your answer as a chemical equation. Identify all of the phases in your answer. Enter noreaction if there is no reaction. = = %

ANSWER: Part C sodium cyanide and ammonium bromide Express your answer as a chemical equation. Identify all of the phases in your answer. Enter noreaction if there is no reaction. ANSWER: Part D potassium hydrogen sulfate and lithium acetate Express your answer as a chemical equation. Identify all of the phases in your answer. Enter noreaction if there is no reaction. ANSWER: Part E sodium hypochlorite and ammonia Express your answer as a chemical equation. Identify all of the phases in your answer. Enter noreaction if there is no reaction. ANSWER: Exercise 17.162 Without doing any calculations, determine which solution in each pair is more basic. Part A ANSWER: Correct Part B ANSWER: 0.100 in 0.100 in 0.0100 in 0.0100 in

Correct Part C ANSWER: Correct Part D ANSWER: Correct Chapter 17 Algorithmic Question 67 Part A If an equal number of moles of the weak acid HCN and the strong base KOH are added to water, is the resulting solution acidic, basic, or neutral? ANSWER: Correct Chapter 17 Algorithmic Question 70 Part A Which one of the following, when 1 mole is dissolved in water, produces the solution with the lowest pH? ANSWER: 0.0100 in 0.0100 in 0.0100 in 0.0100 in neutral basic acidic There is insufficient information provided to answer this question.

Correct Chapter 17 Multiple Choice Question 34 Part A Determine the K b for CN - at 25°C. The K a for HCN is 4.9 × 10 -10 . ANSWER: Correct Chapter 17 Multiple Choice Question 36 Part A Determine the pH of a 0.62 M NH 4 NO 3 solution at 25°C. The K b for NH 3 is 1.76 × 10 -5 . ANSWER: Correct AlCl 3 NaOH NaCl HCl MgCl 2 2.3 × 10 -9 4.9 × 10 -14 3.7 × 10 -7 1.4 × 10 -5 2.0 × 10 -5 2.48 9.45 9.27 11.52 4.73

Exercise 17.101 - Enhanced - with Feedback MISSED THIS? Watch KCV: The Acid-Base Properties of Ions and Salts , IWE: Determining the pH of a Solution Containing an Anion Acting as a Base ; Read Section 17.8. You can click on the Review link to access the section in your eText. Part A Determine of a solution that is 0.150 in . ( for is .) Express your answer in molarity to two significant figures. ANSWER: Part B Complete previous part(s) Exercise 17.105 - Enhanced - with Feedback and Hints MISSED THIS? Watch KCV: The Acid-Base Properties of Ions and Salts , IWE: Determining the Overall Acidity or Basicity of Salt Solutions ; Read Section 17.8. You can click on the Review link to access the section in your eText. Part A Determine whether each of the following salts will form a solution that is acidic, basic, or -neutral. Drag the appropriate items to their respective bins. You did not open hints for this part. ANSWER: = Reset Help Acidic Basic pH-neutral

Exercise 17.157 Part A Calculate the p of a solution prepared from 0.201 of and enough water to make 1.00 of solution. Express your answer using two decimal places. ANSWER: For Practice 17.15 - Enhanced - with Feedback Part A Classify each cation as a weak acid or neutral (neither acidic nor basic). Drag the appropriate items to their respective bins. ANSWER: Chapter 17 Algorithmic Question 73 Part A Which of the following is a polyprotic acid? ANSWER: = Reset Help Weak acid neutral

Correct Chapter 17 Algorithmic Question 75 Part A Calculate the pH of a 0.020 M carbonic acid solution, H 2 CO 3 (aq), that has the stepwise dissociation constants K a1 = 4.3 × 10 -7 and K a2 = 5.6 × 10 -11 . ANSWER: Correct Chapter 17 Reading Question 8 Part A Phosphoric acid, H 3 PO 4 , is a triprotic acid, so both H 2 PO 4 − and HPO 4 2− are also acids. Which of the solutions below would have the lowest pH? 0.1 M NaH 2 PO 4 0.1 M Na 2 HPO 4 0.1 M Na 3 PO 4 Hint 1. Factor to consider Typically, polyprotic acids ionize in successive steps, each with its own K a value. Refer to the table entitled "Common Polyprotic Acids and Ionization Constants at 25°C" to determine the extent to which each species ionizes water. ANSWER: HCN CH 4 HC 2 H 3 O 2 H 2 SO 4 HF 10.25 6.37 1.70 4.03

Correct Exercise 17.117 - Enhanced - with Feedback MISSED THIS? Read Section 17.9. You can click on the Review link to access the section in your eText. Part A Calculate the concentrations of and in a 0.510 solution of ( and .) Express your answers in molarity to two significant figures separated by a comma. ANSWER: Part B Complete previous part(s) Chapter 17 Multiple Choice Question 65 Part A Identify the weakest acid. ANSWER: Correct Exercise 17.28 0.1 M Na 3 PO 4 0.1 M NaH 2 PO 4 0.1 M Na 2 HPO 4 All three would have the same pH because all three are solutions of weak acids. , = H 2 Se H 2 O H 2 Te H 2 S Not enough information is available.

Part A Which factors affect the relative acidity of an oxyacid? Check all that apply. ANSWER: Chapter 17 Algorithmic Question 81 Part A Which of the following is a Lewis acid? ANSWER: Correct Chapter 17 Algorithmic Question 82 Part A Which of the following is a Lewis base? ANSWER: inorganic acids are weak, organic acids are strong electronegativity of the central element inorganic acids are strong, organic acids are weak the number of oxygen atoms attached to the central element the molar mass of an acid CH 4 BCl 3 CHCl 3 NH 3 None of the above is a Lewis acid.

Correct Score Summary: Your score on this assignment is 61.3%. You received 38 out of a possible total of 62 points. C 4 H 10 SiF 4 H 2 O AlF 3 None of the above is a Lewis base.