Question

The table below gives the results from the measurement of the percentage transmission %T of ultraviolet light of wavelength 254 nm for a series of dilute solutions of polystyrene in tetrahydrofuran that were analyzed using a cuvette with a 2.0 mm path length. Using an appropriate plot of the data, determine the molar absorptivity of polystyrene repeat units at 254 nm, giving the value in units of dm3/mol•cm. Polystyrene solution concentration (g/dm3) 0.081 0.167 0.339 0.550 0.689 %T at 254 nm 91.1 82. 6 67. 9 53.3 45.5 Answer:

Answer 1

Given that Polyglyrene Solution convolation (gelm3) 0.081 0.167 0.339 0.550 0689 9111T 82.6 167.953.3745.5 0%. T at 259. nm so оfo Т. CCM) - c(81dm3)/100.1 11=1og(/100) C(gldm3) 91.1 0.040481623 0.081 0.000778098 82.6 0.083019953 0.167 0.001604227 0.339 0.1681 30226 67.9. 0.00395 6484 0.273272791 53:3 0.00528338) 0.55 0.689 0.006618636 145.5 0.341988603 *Abs vs Molor Concertation* 0.4 V-51,688x R=1. 0.3 +65 0.2 0.15 0.1 0.05 0.00500060007 0.003 0004 COM 0 0.0010.002 CS Scanned with CamScanner

om the above quotion. The proccologo op loansmission /T of culturvidet light op wavelength 954 mom and Cunkyard Larry or conveller 07164 2.0 poll length and determine the m y ab Bonplavily op polystyrene repeat Onits al 254 nm). 50. From "Lamben? Benon's law we get" ^ Exlxc --> 0 (Ohere, Aboonbonce t Molar absorptivate l: path dongth ap photo coll in cem c Molari Concontrollon NOW, if we carrymoce equallon a coth general lineare eyn. :: ya ma td - © whole, 'yan 2 =C Slopecm) - (Exl) intercept (l) = 0. 00, we have to convert the concentration canit ofo om g 1 dm 3 HOM hore, q a lmol x 1 dm3 den? dm3. 104-19 12 - Home.) Nes Scanned with . LM CamScanner final 104. 12 10.1

Hence. [morda = | 1 If again ate bance (a $ 407 aste velated as 4.-109 (3400) 80. Now we can explained about plotting 'n only axes con 2 aris so we go follaning lineare equation which in coming through Centro So we have to intercept on a onis in o S lope of reaction @ in 51.688 MY . : Ext 1 -2.0mm 1.6881n! 2,0x10 cm E 51.688m0 -0.2 CM7 02CM = 258.44 m-/m- If the molase aborptivity of polytyrene repeal at 254 om is formula 958.4um-tcm-' IM i. 258.44m-'cm-1 = 258-44 (mol)*' cm' [ .mo . IL-1 am] = 258.44 (ertes D em! - 258.44 moi'amBem! 258.44 dm3/mol.com) cams258,4 dm3) Emol.com) c Seated with