12 14 2016 RWW13 Buffers Paddy Sheehan CH 201 section 002 Fall 2016 Instructor Robert Warren WebAssign RWW13 Buffers Homework Current Score 100 Due Tuesday November 1 2016 11 59 PM EDT The due date for this assignment is past Your work can be viewed below but no changes can be made 1 10 points Select all of the following that would be acceptable conjugate acid base pairs to use in the preparation of a pH 9 8 buffer HF KF H2S KHS KHS K2S KHSO3 K2SO3 KHCO3 K2CO3 HCN KCN HNO2 KNO2 NH4Cl NH3 2 18 points What is the pH of a solution prepared by dissolving 18 mmol of a weak base in 200 mL of a 0 114 M solution of its conjugate acid if pKa 4 16 for the acid pH No Response 4 06 3 18 points How many mL to the nearest mL of 0 159 M KF solution should be added to 280 mL of 0 157 M HF to prepare a pH 4 00 solution No Response 1990 mL KF 4 18 points How many grams to the nearest 0 01 g of NH4Cl Mm 53 49 g mol must be added to 600 mL of 1 221 M solution of NH3 in order to prepare a pH 9 20 buffer No Response 43 97 g http www webassign net web Student Assignment Responses view key dep 14314094 1 2 12 14 2016 RWW13 Buffers 5 18 points What volume to the nearest 0 1 mL of 4 70 M NaOH must be added to 0 300 L of 0 300 M HNO2 to prepare a pH 3 80 buffer No Response 13 7 mL 6 18 points What volume to the nearest 0 1 mL of 4 10 M HCl must be added to 0 650 L of 0 250 M K2HPO4 to prepare a pH 6 50 buffer No Response 33 2 mL http www webassign net web Student Assignment Responses view key dep 14314094 2 2
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