2-17-10 THE 100TH BLOG OF THE YEAR!!!

This blog is a momentous occasion, for it is the 100th blog of our sophomore year of honor's chemistry. Instead of holding a fiesta at my house to celebrate this incredible event, I've gathered an extensive list of truly fascinating facts about the number 100:

• On average, 100 people choke to death on ball-point pens every year (how sad).
• Ben Franklin is on the face of the $100 bill.
• In Greece, India and Israel, 100 is the police telephone number.
• Nicodemus brought 100 pounds of myrrh & aloes to embalm Jesus after his crucifixion.

and here's the 100th blog.......

- To determine the pressure of a gas inside a collection bottle, you would use this equation, which is an instance of Dalton's Law of Partial Pressure:

- P(atmosphere) = P(gas) + P(water)

- If you raise the bottle until the water levels inside and outside the bottle are the same, the total pressure outside and inside will be the same.

- Reading the atmospheric pressure on a barometer and looking up the value of P(water) at the temperature of the experiment in a table (p. 859 in our book), you can calculate the P(gas).

Sample Problem B

- Oxygen gas from the decomposition of potassium chlorate, KClO3, was collected by water displacement. The barometric pressure and the temperature during the experiment were 731.0 torr and 20.0 degrees C respectively. What was the partial pressure of the oxygen collected?

G: Total Pressure = P(atmosphere) = 731.0 torr

P(water) = 17.5 torr (vapor pressure of water at 20.0 C from table A)

P(atmosphere) = P(oxygen) + P(water) ; solve for P(oxygen)

P(oxygen) = P(atm) - P(water)

substitute: P(oxygen) = 731.0 torr - 17.5 torr = 713.5 torr

- Boyle's Law

- Robert Boyle discovered that doubling the pressure on a sample of gas at constant temperature reduced its volume by 1/2

- explained by the Kinetic-Molecular Theory (Dr. B said to make sure and know this!)

- the pressure of a gas is caused by moving molecules hitting the container walls

- if the volume of the container is decreased, more collisions will occur and the pressure will increase

- if the volume of the container is increased, less collisions will occur and the pressure will decrease

- Boyle's Law states that the volume of a fixed mass of gas varies inversely with the pressure at constant temperature.

- Formula: PV=K (P=pressure, V=volume, K= constant)

-the inverse would be a straight line (V=K/P)

- Because of the transitive property of equality, since two different quantities are equal to the same thing (volume x pressure = K), it can be concluded that two separate sets of conditions are equal to each other (P1V1 = P2V2)

That's the blog, have a wonderful night.