Question

*SHOW YOUR WORK*

(Boyle's Law):

1. What is the final volume (in mL) or argon gas is 50.0 mL at 705 torr is compressed to a pressure of 2.75 atm, at constant temperature?

(Lewis Dot Structures):

2. Draw Lewis structures for the following molecules. Include partial charges, AXE designation, (example: AX2 E2), Electron-pair geometry and geometric-molecular shapes. Is it Polar or Non-Polar?

CH2Cl2

SO2

3. Which of the following explains why the pressure of a gas increases when the temperature increases (volume remaining constant)?

a) the kinetic energy of gas molecules increase

b) the velocity of gas molecules increases

c) the collision frequency of gas molecules increases

d) all of the above

e) none of the above

(Dalton's law of partial pressures)

4. In a reaction, "wet" oxygen gas was produced at 23.0 C. What is the pressure (in atm) of oxygen gas, if the atmospheric pressure is 761.0 mm Hg?

5. What is the final "Celsius" temperature if 2.40 L of gas at 30.5 C is cooled until the volume reaches 1.00 L at constant pressure?

6. According to the combined gas law, the pressure exerted by a gas is:

a) directly proportional to volume and kelvin temperature

b) inversely proportional to volume and kelvin temperature

c) directly proportional to volume and inversely proportional to the kelvin temperature

d) inversely proportional to volume and directly proportional to the kelvin temperature

e) none of the above

7. A sample of gas occupies 555mL at 175 cm Hg and a temperature of 37.0C. What is the new volume (in mL) at STP?

8. If 0.795 moles of ammonia gas occupies 42.5 L at 670 torr, what is the Celsius temperature?

9. Which of the following is NOT true according to the kinetic theory of gases?

a) molecules occupy negligible volume

b) molecules move randomly in straight line paths

c) molecules are NOT attracted to one another

d) molecules lose energy after colliding

e) molecules have the same kinetic energy at the same temperature

10. (Lewis Dot Structures):

Draw Lewis structures for the following molecules. Include partial charges, AXE designation, (example: AX2E2), Electron-Pair Geometry and Geometric- Molecular Shapes. Is it a Polar, or Non-Polar Molecule?

N2

SO3^-2

11.Which of the following changes decreases the pressure in a gaseous system?

a) decreasing the volume

b) increasing the temperature

c) increasing the number of gas molecules

d) all of the above

e) none of the above

12. Two bottles of gases are sitting on a shelf at 25C. Bottle A contains hydrogen gas and bottle B contains helium gas.

A) In which bottle do the molecules of gas have the higher average Kinetic energy?

B) In which bottle are the molecules moving faster (have a higher average velocity)?

C) If not the same velocity, by how much faster is the velocity of the gases?

13. If 0.0469 g of Mg metal reacted with hydrochloric acid completely, temperature is 21.0 C barometric pressure is 759.0 mm Hg, and the product was collected by volume by water displacement; how much volume of gases would be measured in mL? SHOW YOUR WORK!

A) What is the temperature in Kelvin?

B) What is partial pressure due to water vapor at 21.0 C?

C) What is partial pressure of the hydrogen gas, PH2 (in atm)? *remember Dalton's law of partial pressures for a "wet" gas*

D) What is moles of hydrogen gas created in moles?

E) What is the Ideal Gas Law Constant, R (in atm-L/mole- K) ?

F) What is the working equation for Volume ( using PV= nRT)

G) What is the volume of gases in mL?

14. Could this amount of magnesium metal be used in our laboratory experiment that we performed in lab? If not, explain why.

Answer 1

The volume at 2.35 atm pressure is 19.7 mL.