Question

3. Short Answer Questions: (4 pts each a. A balloon that is 70.21 L at 12.1 degrees Celsius and 715 torr is released and just barely clears the top of Mt. Crumpet, near Whoville. If the final volume of the balloon is 88.53 L at a temperature of 2.28 degrees Celsius, what is the pressure experienced by the balloon as it clears Mt. Crumpet? (R = 0.0821 Latm/molK) b. Use kinetic molecular theory of gases to explain Boyle's Law relating volume to pressure. c. What are the two reasons for deviations in the Ideal Gas Law? 4. A solution of Ca(OH)2 (aq) is neutralized with 2.50 M HCl (aq) and the buret readings are shown below. Write a balanced molecular reaction for this neutralization. What is the concentration (M) of the Ca(OH), (5 pts)? HCl: Final Volume 41.15 mL Initial Volume 6.34 mL Ca(OH)2 Final Volume 46.42 mL Initial Volume 33.31 mL

Answer 1

a. We use the ideal gas relation: P * V / T = constant, P is pressure, V is volume and T is temperature in K:

Using the initial values and Assuming pressure P in the final state:

715* 70.21 / 285.1 = P * 88.53 / 275.28

Solving, P= 547.51 torr

b. From the Kinetic theory of gases, we have the relation: K.E = 3/2 RT

We see thast according to this theory, we see that energy remains constant at constant temperature and that pressure arises from the collision of gas molecules. NOw it is easy to infer that if gases are packed together more closely, they collide more frequently making a higher pressure, while spread out molecules collide lesser meaning lower pressure. This gives us an idea that P inversely proportional; to V at constant temperature

c. 1. Intermolecular forces of attraction

2. Volume of gas is negligible compared to Volume of container