Calculations Remember Work Alone On Lab Reports And Always Show Your Work You Must Use Dimensional Analysis For Quest 1 (43.8 KiB) Viewed 13 times
Calculations Remember Work Alone On Lab Reports And Always Show Your Work You Must Use Dimensional Analysis For Quest 2 (27.4 KiB) Viewed 13 times
CALCULATIONS Remember: work ALONE on lab reports - and always show your work You must use dimensional analysis for questions #2, #6, 18, and 99 1. Calculate the surface area of the monolayer (= water surtace) (in cm) using the calipers measurement A== 1.5 cm 3. 75cm REIS (31) 2. Calculate the grams of stearic acid molecules used to form the monolayer in each trial via dimensional analysesta with #of drops to form monolayer x average volume per drop (mL/drop). You will be using the calculation you entered below the table on p. 2, and you will need to use the concentration of the stearic acid solution. Do this for each T1: 7 drops 0,01 mL 0.19 000000-1 14 drop - T2 q drop o.olme Troom a.lg..st -0.0ooot Tral 1:000 18 Trial 2 000 000 15.5 Average 0.00000 3. Use the density of pure stearic acid (0.941 g/mL) to calculate the volume of stearic acid in an average monolayer use the average mass from calculation #2) VE 0.0000098 18.502x lo ML V 0.941gime Do 4 Use the fact that volume = area x thickness to calculate the thickness of the monolayer in cm 8.502 Xlo 44.18 1 5. If we assume that each molecule of stearic acid is six times longer than its diameter and that has a cylindrical shape, the volume of each molecule can be expressed by the following equation, where is the monolayer thickness ਦੀ Use this equation and your result for calculation $4 to find the volume of a single molecule in ml 8.502x10 me long .9.24x10 cm V 144 V=T(19277707 11. 55x1020 mL 6. Use the density of stearic acid (g/mL), the volume of a molecule (mLimolecule), and the fact that 1 mole of steare acid = 284 g to calculate the number of molecules per mole by dimensional adalyas Since you are trying to calcu Avogadro's number, you cannot use 6.022 x 10 to solve this problem! 2849 1 mole
7 Comment on the accuracy of your result for #6: how does it compare to the expected value for Avogadro's number? A reasonable answer for #6 in this experiment is within a power of 10 of the expected result (use ONE completa sentence; refer to your result and the expected result clearly 3. Using your molecular volume (mL/molecule, #5): how many molecules are in 8.15 nL of this compound? Use dimensional analysis (and use the expected value for Avogadro's number Suppose a different fatty acid molecule were used, with a molar mass of 197 g/mol and a density of 0.852 g/mL Use the expected value for Avogadro's number with dimensional analysis to calculate its molecular volume (mL/molecule
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