l llRUM ethanol Kristina Tuckerman Word PAGE LAYOUT TABLE TOOLS REFERENCES MAILI

Question

l llRUM ethanol Kristina Tuckerman Word PAGE LAYOUT TABLE TOOLS REFERENCES MAILINGS REMEw VIEW DESIGN LAYOUT A A Aa x, x' A. A IF AaBbodDo AaBbcoDo AaBbco AaBbcct AaBl Font l: -la. B 1Normal l No Spac... Heading 1 Heading 2 AaBbccc Aa 1 Paragraph Title Subtitle sub Styles Experiment 1: Calculating the Molar Mass of Ethanol In this experiment you will determine the molar massof ethanol using the vapor density of a 95% ethanol solution. Because a 95% ethanol solution is used, the resulting molar mass that is calculated would be incomect, due to the water in the solution. To correct for this, the water must be drawn off using a molecular sieve. Procedure Preparation of Ethanol Put on your safety glasses and gloves (provided in your safety box). Turn on the scale by pressing the button labeled orT lfyour scale does notturn on, you may have to remove the battery cover and remove a small strip of plastic from the battery housing. Once the scale is on, press the '0/T button a second time to zero the scale. Make sure that the units are in grams (g). If not, press the M button until the units displayed are in grams. Place a weigh boat on the scale and zero the mass of the weigh boat by pressing the "OT" button. Your scale should now read 0 g

Explanation / Answer

1. Experimental molar mass,
   PV =nRT
   0.9969 atm *0. 275L = n*0.0821 atm L mol-1K-1 349.5K
n = 9.55419*10-3 mol
   molar mass exp = (4.29-3.83) gm / 9.55419*10-3 mol = 48.1464 gm/mol approx.
   actual molar mass = 46.06844 g/mol
percent error = [ (48.1464-46.06844) / 46.06844 ] * 100 = 4.5105 %
Experimental value is 4.5105 % higher than the real value

2. Then the mass of the ethanol collected would be less which would result in decreased
   molar mass of ethanol.

3. The mass of the air will add up to the condensed ethanol but the air will not condense,
   therefore mass of ethanol will be less in this case and molar mass will be low.

4. There will less condensed liquid which will result in reduced molar mass

5. If water is present then the number of moles of ethanol will be less which results in increase
   of the molar mass.

6. Sieves help in removing water from ethanol, an optimum number of sieves for the experiment
   will always result in favourable outcomes

Related Questions

Navigate

• Browse (All)
• Browse L
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.