In an experiment reported in the scientific literature, male cockroaches were ma

Question

In an experiment reported in the scientific literature, male cockroaches were made to run at different speeds on a miniature treadmill while their oxygen consumption was measured. In one hour the average cockroach running at 0.08km/hr consumed 0.8 mL of O2 at 1 atm pressure and 24 ?C per gram of insect weight.

a)

How many moles of O2 would be consumed in 1 hr by a 5.4?g cockroach moving at this speed?

b)

This same cockroach is caught by a child and placed in a 1-qt fruit jar with a tight lid. Assuming the same level of continuous activity as in the research, will the cockroach consume more than 20% of the available O2 in a 48-hr period? (Air is 21 mol percent O2)

Explanation / Answer

PV=nRT
n = PV/RT = 1 atm x 0.0008 L / (0.08206 x 298 K) = 3.27x10^-5 mol/gram
3.27x10^-5 x 5.2 g = 1.70x10^-4 mol O2

(a) 1.70x10^-4 mol O2
1 qt = 32 fl oz x 29.57 ml/fl oz = 946 mL/quart
1.70x10^-4 mol/hr x 48 hr = 0.00816 mol O2 in 48 hr
moles of air in quart jar-
n = 1 atm x 0.946 L / (0.08206 x 298 K) = 0.03868 mol air
0.21 x 0.03868 = 0.00812 mol O2
20% of available O2 = 0.20x0.00812 = 0.00162 mol

(b) Cockroach will consume more than 20% of available O2 in 48 hr
total O2 = 0.00812 mol
20% of available O2 = 0.00162 mol
consumed in 48 hr = 0.00816 mol

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

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