Lab 8 - Using the Ideal Gas Law PDF

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Using the Ideal Gas Law with Experiment Pictures...

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Lab 8 Using the Ideal Gas Law

CHEM101L

Student Name: Robert Prieskorn Access Code (located on the lid of your lab kit): AC-GNJ4O07 Pre-Lab Ques?ons: 1. Write the balanced equa2on for the decomposi2on of hydrogen peroxide. 2H2O2 --> 2H2O+1O2 2. According to Charles’s law, what is the rela2onship between temperature and pressure? According to Charles’s law, when the pressure of a gas is held constant, increasing it’s temperature increases it’s volume. Charles’s law states that the volume occupied by a fixed amount of gas is directly proportional to it’s absolute temperature if the pressure remains constant. 3. Atmospheric pressure depends on the al2tude (or height) of your loca2on. How should the air pressure change if you were in Denver, Colorado, which is 1.5 kilometers (1 mile) above sea level? It should be lower than that of sea level. Increased Altitude = decreased atmospheric pressure. 4. Considering that catalysts are not consumed in a reac2on, how do you think increasing the amount of catalyst would affect the reac2on rate for the decomposi2on of hydrogen peroxide? It would increase the decomposition rate. Experiment 1: Charles’s Law Table 1 Temperature vs. Volume of Gas Data

Temperature Condi?ons

Temperature (˚C)

Volume (mL)

Room Temperature

21°C / 294.15°K

1.4mL

Hot Water

50°C / 323.15°K

2.6mL

Ice Water

0°C / 273.15°K

0.2mL

Post-Lab Ques?ons 1. Use a pencil and graph paper to create a graph of temperature and volume data. Place temperature on the x-axis (in Kelvin) and volume (mL) on the y-axis. Leave room on the leT side of your chart for temperature values below zero. You can also use a graphing program to create your graph. Using a ruler, draw a straight line of best fit through your data points, extrapola2ng the line un2l it intersects the (nega2ve) x-axis.

Lab 8 Using the Ideal Gas Law

CHEM101L

2. Why can you assume a linear rela2onship (a straight-lined slope)? I can assume a linear relationship because of the constant pressure 3. What happened to the volume of gas when the syringe was exposed to various temperature condi2ons? Using the concepts explored in the Introduc2on, describe why this occurred, keeping in mind the defini2on of temperature. Referencing back to pre-lab question 2, increasing the temperature results in an increased volume. When the syringe was introduced to the hot water the air space expanded. When the syringe was introduced to the ice water the air space reduced. 4. At what temperature does your line intersect the x-axis? What volume corresponds to this temperature? The line intersects at the X-Axis at approximately 270.15°K. The volume equals a volume of zero mL. Insert a photo of your completed lab setup with your name and access code handwriNen in the background:

Lab 8 Using the Ideal Gas Law

CHEM101L

Experiment 2: Using the Ideal Gas Law Table 2 Temperature, Pressure and Volume Data Temperature of Dis?lled H O: 2

22°C

Room (or regional)

Ini?al Volume

Final Volume of Air

Pressure

of Air (mL)

(aWer reac?on) (mL)

(Final Volume - Ini?al Volume)

30mL

70mL

40mL

(atm): 1.0atm

Volume of O Collected 2

Table 3 Reac?on Time Data Time Reac?on Started

Time Reac?on Ended

Total Reac?on Time

14:11

14:15

4 minutes

Post-Lab Ques?ons 1. What would happen if you added more than five mL of yeast to the H2O2? If 5 more mL of yeast is introduced to the experiment the reaction will be quicker/ increased. The yeast acts as a catalyst for the decomposition of the Hydrogen Peroxide. 2. What would happen if you added more than 5 mL H2O2 to the 5 mL of yeast?

Lab 8 Using the Ideal Gas Law

CHEM101L

If 5 more mL of Hydrogen Peroxide is added to the experiment the decomposition rate is decreased slowing the reaction. 3. What was going on in the graduated cylinder as the H2O was pushed out? As water was being expressed the formation of gas bubbles were observed in the graduated cylinder. 4. How would the number of moles (n) of O2 change if your atmosphere was doubled and all other variables stayed the same? If the atmosphere is doubled the number of oxygen moles are doubled as well. 5. How would the number of moles (n) of O2 change if your temperature was doubled and all other variables stayed the same? If the temperature is doubled the number of moles of oxygen will decreased by half of it’s value. 6. In this experiment, the temperature of the gas evolved is equal to the temperature of the water in the beaker, which ideally should be the same as the air temperature. Explain how the volume of oxygen evolved would change if you used ice water instead of room temperature water. How would it change if you used boiling water? If ice water were used in place of room temperature water the volume of oxygen evolved would be less. If the experiment was conducted with boiling water the volume of oxygen would be greater.

Insert a photo of your completed lab setup with your name and access code handwriNen in the background:

Lab 8 Using the Ideal Gas Law

CHEM101L...