Question
REPORT FOR EXPERIMENT 19 (continued) NAME 5. On the graph paper provided, plot the volume-temperature values used in Calculation 4. Temperature data must be in C. Draw a straight line between the two plo extrapolate (extend) the line so that it crosses the temperature axis QUESTIONS AND PROBLEMS 1. (a) In the experiment, why are the water levels inside and outside the flask equalized before removing the flask from the cold water? (b) When the water level is higher inside than outside the flask, is the gas pressure in the flask higher than, lower than, or the same as, the atmospheric pressure? (speci- fy which) 2. A 125 mL, sample of dry air at 230°C is cooled to 100°C at constant pressure. What vol- ume will the dry air occupy at 100°C?
Explanation / Answer
Question 2
Moles of dry air in constant pressure
PV=nRT
V = 125 ml = 0.125 Liter n = Moles = ?
R = 0.0821 L atm K-1 atm-1 T = 273 + 230 = 503K
n = V / RT
n = 0.125 / 0.0821 x 503 = 0.0030269 Moles
using the mole value we can calculate the volume in new temperature
V = 0.0030269 x 0.0821 x 373
Volume = 0.09269 Liter or 92.6 ml