p11 to 14 solutions

Avogadro's Law

6.         Avogadro's Law: same temperature and pressure, same volume, so we have the same number of molecules (and hence moles). Answer C is true and so is D because of the kinetic theory.

7.         Their lungs have the same volume; biologists would say that their lung capacity is the same.

8.         B

9.         2.5 moles will also have a volume of 20.00 L (Avogadro's law) , so with three times as many moles we will have three times the volume:

            Answer 60 L

Boyle's Law

10.       a.         P1V1 = P2V2 at constant temperature.

            b.         see top of page 9 in blue booklet

11.       As the balloon ascends it encounters lower atmospheric pressure ( less molecules are weighing down at a higher altitude). With lower pressure, volume increases, assuming that the temperature change is negligible.

12.       P1V1 = P2V2.

            900 V1 =100 V2.

            V2/V1 = 9, so the volume becomes 9 times bigger.

13.       P1V1 = P2V2.

            75(1) = P2(1 + 2)

            P2 = 25 kPa.

14.       P1V1 = P2V2.

            P1(30.9) =300(20.4)

            P1 = 198 kPa

Gay Lussac Law

15.       see page 10

16.       119 kPa           (don't forget to convert to Kelvin before applying ratio)

17.       P2/P1  = 300/273 = 1.10

18.       977 K = 704 oC


The longer arrows represent higher temperatures. ( because the molecules move faster, in a given time interval, they will travel further. But because of this they will collide more often with the walls of the their container (more pressure)

Understanding Atmospheric Pressure

20.       a.         With a vacuum there is no weight inside the tube to counter the atmospheric pressure outside of the tube. But the weight of the air is limited, so it will only push the water up to a certain height.

            b.         Since mercury is 13.6 times as dense as water(1.00 g/ml) it will only rise 1/13.6 times as high as water, so 10.3 m/13.6 = 0.757 m, which is approximately the atmospheric pressure expressed in mm (760 mm)

            760 mm = 1 atm = 101.3 kPa = 14.7 psi(pound per square inch)