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http://w w w.sapling earning com ibiscms/ mod/ibis ! T Home-Welcome to Toshiba CHM 1045-Genera Cheml , X chemistry question Chegg co. eNew tab Attempts Score 4. -Print Calculator -Periodic Table Available From 2/5/2016 10:00 AM Due Date: Points Possible 100 Grade Category Graded Description: Policies: 19 100 Question 30 of 33 2/16/2016 11:00 PI 20 Mapt University Science Books presented by Sapling Learning Donald McQuarrie Peter A. Rock Ethan Gallogly 21 100 The amount of nitrogen in an organic substance can be determined by an analytical method called the Kjeldahl method, in which all the nitrogen in the organic substance is converted to ammonia. The ammonia, which is a weak base, can be neutralized with hydrochloric acid, as described by the equation CHM 2211 NH3(aq) + HCl(aq) NH4 Cl(aq) 100 You can check your answers. If 20.0 mL of 0.150 M HCI(aq) is needed to neutralize all the NH3(g) from a 2.25-g sample of organic material, calculate the mass percentage of nitrogen in the sample 24 You can view solutions when you comp up on any question. You have three attempts per question. There is no penalty for incorrect answe 25 100 Number 26 27 100 Help With This Topic Web Help & Videos Technical Support and Bug Reports 28 100 31 32 75 Previous Give Up & View Solution e Check AnswerNext Exit Hint 100 Copyright © 2011-2016 Sapling Learning, Inc.-151 about uscareersps privacy policy terms of usecontact us help 23:30 TI 2/14/2016Explanation / Answer
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Dear candidate you have asked too many questions. As per guidelines one question one time should be posted. Here we solve first question. Please send other questions separately.
NH3 + HCl ------> NH4Cl
As per the stiochiometry of the reaction one mole of HCl react with one mole of NH3.
Moles of HCl reacted = volume of HCl X Molarity of HCl = 20mL X 0.15 = 3.0 mmols
moles of ammonia formed from organic compound = moles of HCl reacted
Hence moles of ammonia = 3.0 mmoles
Since one mole of ammonia contains one mole of Nitrogen, therefore moles of Nitrogen presen in the compound = 3.0 mmoles
mass of Nitrogen = No. of moles X atomic mass = 0.003 X 14 = 0.042g
3.0 mmoles = 3.0 / 1000 = 0.003 moles
mass % of N in the compound = (mass of N / mass of the compound ) X 100
mass % of N in the compound = (0.042 / 2.25) X 100 = 1.87%
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