Review ToP LRD Pal A student placed I\'sn. of am unknown volaile iquid into a 25

Question

Review ToP LRD Pal A student placed I'sn. of am unknown volaile iquid into a 250mL Erlenmeyer flask (mass of flisk was 63 498 p The flask was immersed in a water bath at 99°C for 8 minutes and at an atmospheric pressure of 757 mmHg allowing the liquid to vaporize. The flask was then removed, the vapor condensed and the mass of the flask plus the condensed vapor was determined to be 64.738 g. The student filled the cleaned flask to the top with water and determined the mass of the flask and water was 328.45 grams a. b. c. mass of the vapor temp of gas in K = pressure of the vapor in atm- moles of gas present- molar mass of gas= e.

Explanation / Answer

mass of the vapour = 64.738 g - 63.498 g = 1.24 g

temperature in K (T) = 99 + 273.15 = 372.15 K

Pressure of the vapour in atm P = 757mmHg * 1 atm/760 mmHg = 0.9961 atm

mass of water = 328.45 - 63.498 = 264.952 g

volume of water = volume of flask

volume of water (from density of water 1g/mL) = 264.954 mL = volume of the flask

molar mass of the gas from the ideal gas equation

PV = (m/M)*RT

m = mass of the gas

M = molar mass of the gas

R = gas constant

0.9961 * (264.952 * 10^-3) = 1.24/M * 0.0821 * 372.15

M= molar mass of the liquid = 143.55

number of moles of the liquid = 1.24/143.55 = 8.638 * 10^-3 moles

Related Questions

Navigate

• Browse (All)
• Browse R
• Subjects

---

---

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