jessie

This exercise uses the population growth model. 

A certain culture of the bacterium Rhodobacter sphaeroides initially has 30 bacteria and is observed to double every 5 hours.

1. The average molecular speed in a sample of gas at a certain temperature is 591 m/s.

The average molecular speed in a sample of gas is _______     m/s at the same temperature.

2.A sample of gas is observed to effuse through a pourous barrier in 5.41 minutes. Under the same conditions, the same number of moles of an unknown gas requires 9.71 minutes to effuse through the same barrier.

The molar mass of the unknown gas is   

______   g/mol.

Which of the following gas samples would have the largest volume, if all samples are at the same temperature and pressure?

1.33 moles CH4

111.4 grams of Kr

8×1023 molecules of O2

they would all have the same volume

Which of the following gas samples would have the largest volume, if all samples are at the same temperature and pressure?

9×1023 molecules of H2

3.01 moles CH4

168 grams of Kr

they would all have the same volume

1.   A sample of krypton gas collected at a pressure of 1.46 atm and a temperature of 300. K is found to occupy a volume of 663 milliliters. How many moles of Kr gas are in the sample? 

______      mol

1.  A 0.168 mol sample of an unknown gas contained in a 8.00 L flask is found to have a density of 0.867 g/L. The molecular weight of the unknown gas is

_____     g/mol.

2.  A 0.156 mol sample of Kr gas is contained in a 6.00 L flask at room temperature and pressure. What is the density of the gas, in grams/liter, under these conditions? 

 ______    g/L

A 0.622 mol sample of N2 gas is confined in a 14.5 liter container at 12.0 °C. 

If the temperature of the gas sample is decreased to -9.30 °C, holding the volume constant, the pressure will decrease because:

Choose all that apply.

With lower average speeds, on average the molecules hit the walls of the container with less force.

With higher average speeds, the molecules hit the walls of the container more often.

At lower temperatures molecules have lower average speeds.

As the number of molecule-wall collisions increases, the force per collision decreases.

None of the Above

1. A sample of neon gas at a pressure of 706 mm Hg and a temperature of 30 °C, occupies a volume of 12.1 liters. If the gas is heated at constant pressure to a temperature of 69 °C, the volume of the gas sample will be 

____ L.

2.  A sample of krypton gas at a pressure of 0.965 atm and a temperature of 241 °C, occupies a volume of 651 mL. If the gas is heated at constant pressure until its volume is 943 mL, the temperature of the gas sample will be 

____ °C.

A sample of krypton gas collected at a pressure of 1.46 atm and a temperature of 300. K is found to occupy a volume of 663 milliliters. How many moles of Kr gas are in the sample?

_____ mol

1. A sample of an unknown gas is found to have a density of 1.42 g/L at a pressure of 1.01 atm and a temperature of 32 °C. Assume ideal behavior.

The molar mass of the unknown gas is 

____    g/mol.

2. A sample of sulfur dioxide gas has a density of

_____    g/L at a pressure of 1.34 atm and a temperature of 42 °C. Assume ideal behavior.

1.  A 1.80 mol sample of Ar gas is confined in a 42.9 liter container at 17.1 °C. 

If the temperature of the gas sample is raised to 34.1 °C holding the volume constant, the average kinetic energy will

decrease

not enough information to answer the question

remain the same

increase

1. A sample of neon gas at a pressure of 706 mm Hg and a temperature of 30 °C, occupies a volume of 12.1 liters. If the gas is heated at constant pressure to a temperature of 69 °C, the volume of the gas sample will be 

____ L.

2. A sample of krypton gas at a pressure of 0.965 atm and a temperature of 241 °C, occupies a volume of 651 mL. If the gas is heated at constant pressure until its volume is 943 mL, the temperature of the gas sample will be 

_____ °C.

1. A sample of krypton gas at a pressure of 0.634 atm and a temperature of 21.0 °C, occupies a volume of 17.0 liters. If the gas is compressed at constant temperature to a volume of 10.7 liters, the pressure of the gas sample will be 

____ atm.

2. A sample of methane gas at a pressure of 0.754 atm and a temperature of 23.5 °C, occupies a volume of 432 mL. If the gas is compressed at constant temperature until its pressure is 1.18 atm, the volume of the gas sample will be 

____ mL.

What volume of Ar at 45°C and 1.5 atm contains the same number of particles as 0.655 L of H2 at 15°C and 3.00 atm? Write the answer in the box with the correct number of significant figures. Use Liters as unit of measure of the volume. Don't write the units in the box.

Ok so I was walking up the stairs one time and there was a Spanish guy while I was walking the stairs to go upstairs and he followed up upstairs like he was about to rape me or touch me or do anything to me and I didn’t see his face and he was following the stairs the other side too from across from me and I didn’t see his face and I felt him smiling I think. Then I ran up the stairs and he was running up the stairs from across from me on the stairs like he was abut to rape me or follow me to kill me or murder me and I didn’t see him once I ran up the stairs and I went into my apartment forcing and twitching the doorknob right to open and I was scared and became scared the whole time while running up the stairs and he was following me on the stairs across from me once I made it up my apartment but I didn’t see him and I know he didn’t make it up the same time as me once I made it to the front of my apartment and inside my apartment. I’m old now and traumatized from now. What do you think of this situation and what should I do?