Question

11 WIBUS. 19. Percent composition problems (Empirical formula and Molecular formula) A. Fructose, C6H12O6, is a sugar commonly derived from corn and is 1.73 times as sweet as sucrose. Calculate the percent composition of carbon, hydrogen and oxygen in fructose. B. An unknown compound is found in tree sap. It has been shown to be composed of 40.0% carbon, 6.7% hydrogen and 53.3% oxygen by mass. It was also discovered the 5.00 moles of the material has a mass of 900 grams. What is the empirical and molecular formula of this compound? C. Determine the percent composition of each of the elements in Na3PO4 to the nearest tenth of a percent. D. Sarin is a powerful nerve agent which even in low doses results in death within one minute. It consists of C 34.29%, H 7.19%, F 13.56%, O 22.84%, P 22.11%. With a molecular weight of 140.09 g/mole what is the empirical and molecular formula?

Answer 1

Moleular oumula d tuctose = CM2O6 = (C,0), Impewcal qoumala fucton CH20 quam oeach elements im Chg0 129 imele) o g (2mole) H 1male o 0 16 Empircical 12+2t16= 30 9 Mars mau /o C mas o elamant X loo Cempound X lo0 = 40 1. 30 Molar mau mam loo= 6.67. 30 /. may / 30 A/00= 53.33

(B o loog umkmeron cempound, 40 0 Myduogen69 mai Cauben mars 6.7 53-3 mars towest valur malos oCauben 3.33 umele 40 males otydun 67-6.mele 1 meles o O 53-3 3.33 mele 16 Ouvide uall value uuth the lowest value C = 3.33 H6.4 3.33 1 0:3.33 1 3.33 3. 33 C420 (MM30gel Empinical Youmula CM,0, for 5mele or 1 vmele its moleular mas = 900 am 900 ab molecular mam - 180 m=Moleuular Mas Empurial Mas Me6 3 0 Moleular oumula Empiuial umula)m = (CK,0)6 C&M1206

foumula i Na, P04 (c) NaE 699(3mole) Vmass 1 81a (tmole) 649 (4mele) Nag PO4= 16g P mau 0 mam Molecular man 69 $ mars 42.1. Na -X100 164 31 164 mam 1 64 -Xl00 = 39.0 1 0 D) per toog Cempound C = 34 34 0 22-84 H1.12 F-13. P moles o C 34.29 2.85 12 moler 0-22-8 16 1 43 moles o H= 319 719 moles a P 22-11 0.71 31 moles o F -13.56 -0.71 19 lowest valu Aivide au valu uth Lowest valus,

C:.95 4 0 1.43 0.7H H: 719- 10 P: 0.7H - 1 0 7H F 0.1 1 Empirical Foumula = CHIF2P 140 Cmpinial tormula meleular Weht 140gmet Max Molecular weight Empwial 4ormula mau 140 09 140 1 Molecular toumula = Cy1o FOP I!