8_new - Exam #2 holcombe (51160) This print-out should have...

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Exam #2 – holcombe – (51160) 1 This print-out should have 30 questions. Multiple-choice questions may continue on the next column or page – find all choices before answering. 001 10.0 points Everyone should recognize that ? is a strong acid, ? is a weak acid, ? is a strong base, and ? is a salt. 2. HCl; HCN; Cu(OH) 2 ; LiCl 3. HNO 3 ; HCN; KOH; LiCl correct 4. CH 3 COOH; HF; KOH; KBr 5. HNO 3 ; HCN; KOH; CO 6. HCl; HNO 3 ; NaOH; LiCl Explanation: Of the answer choices, hydrochloric acid (HCl) and nitric acid (HNO 3 ) are strong acids because they dissociate completely in water. Acetic acid (CH 3 COOH) and HCN are weak acids due to their partial dissocia-tion. Sodium hydroxide (NaOH) potassium hydroxide (KOH) are strong bases, dissoci- ating completely to yield hydroxide (OH ). Lithium chloride (LiCl) and potassium bro- mide (KBr) are salts, compounds composed of a cation (metal) other than H + and an anion (non-metal) other than OH or O 2− . 002 10.0 points Which of the following salts produces a neu- tral solution when it is dissolved in water? 1. KCH 3 CO 2 2. NaClO 3. KCN 4. LiF 5. NaBr correct Explanation: 003 10.0 points If you add 0.001 moles of potassium nitrate to a liter of water, what will be the pH of the solution? 1. 1 2. 14 3. 11 4. 3 5. 7 correct Explanation: n KNO 3 = 0.001 mol V = 1 L Potassium nitrate is KNO 3 . It dissociates into K + and NO 3 . Since it doesn’t contribute H + or OH , it doesn’t change the pH. The pH of water is 7; therefore the solution’s pH is 7. 004 10.0 points What is the pH of a 6.40 ×10 −5 M HNO 3 solution? 1. 4.92 2. 3.19 3. 5.19 4. 4.19 correct 5. 5.76 Explanation: [HNO 3 ] = 6.40 × 10 −5 M pH = − log[H + ] = − log(6.40 × 10 −5 ) = 4.19 005 10.0 points Adding NH 4 BrO to pure water would result in what kind of solution? K a for HBrO is 2.5 × 10 −9 and K b for NH 3 is 1.8 × 10 −5 .
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Exam #2 – holcombe – (51160) 2 1. neutral 2. basic correct 3. acidic Explanation: 006 10.0 points What is the pOH in a solution made by dissolving 0.100 mole of sodium acetate (NaCH 3 COO) in enough water to make one liter of solution? K a for CH 3 COOH is 1 . 80 × 10 −5 . 1. 8.87 2. 9.25 3. 5.13 correct 4. 1 . 80 × 10 −6 5. 1 . 34 × 10 −3 6. 5.74 7. 1 . 34 × 10 −9 8. 2.87 9. 7 . 46 × 10 −6 10. 5 . 56 × 10 −10 Explanation: 007 10.0 points Which of the following is the conjugate base of H 2 PO 4 ? 1. H 3 PO 4 2. PO 3 4 3. OH 4. HPO 2 4 correct Explanation: The conjugate base of H 2 PO 4 will have one less H + ; I.E. , HPO 2 4 . 8 10.0 points A solution with a higher pH is more acidic. 1. True 2. False correct 3. The answer cannot be determined with-out additional information. Explanation:
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8_new - Exam #2 holcombe (51160) This print-out should have...

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