Question

draw the Lewis structure of a gaseous

DETERMINATION OF THE MOLAR MASS OF A VOLATILE COMPOUND Post Lab Discussion Questions: How did this lab conform to the 12 Green Principles of Chemistry? Which Principles? 1. 2. What improvements could be made to this lab? Any improvements to make this lab "greener"? Were there any parts to this lab that violated the 12 Principles? If so, which ones and why? 3. Draw the Lewis structure of a gaseous hydrocarbon (2.55 grams of which) that occupies a vessel of volume of 3.00 L at 0.950 atm and 82.0 "C. 4. Why is the Kelvin temperature scale necessary? 5. According to Charles's Law, the temperature of a sample of gas is proportional to its volume -your roommate explains this to you by telling you that a gas sample will double in volume as the temperature is raised from 25 C to 50 "C. Do you agree? Why or why not? 6.

Answer 1

4) Let M is molar mass gaseous hydrocarbon.

Volume (V) = 3 liters

Pressure (P) = 0.950 atm

Temperature (T) = 82°C = 273 + 82 = 355 K

Let n is mole of hydrocarbon.

Gas constant (R) = 0.0821 L atm/mol K

PV = nRT

n = PV/RT = 0.950 * 3 / 0.0821 * 355

n = 0.0978 moles

Mass = moles * molar mass

2.55 = 0.0978 * M

M = 26.08 g/mol

So, the hydrocarbon is C2H2 (ethyne).

Lewis dot structure is:

Н.— СЕ Схонок нC = C-н