Name _________________________________________
HONORS Homework #4
Purple Due: October 8 & Green Due: October 9
Standard Temperature & Pressure
1. What are the values and units for STP?
a. 0°C & 1atm
c. 1°C & 0atm
b. 25°C & 1atm
d. 0K & 1mmHg
Temperature Conversions
2. Temperature is more than just how hot or cold something is because ____.
a. it includes Kelvin measurements
c. it is a feeling you get when you step outside
b. it discusses the average kinetic energy of
particles
3. Convert 25°C to Kelvin.
25C + 273 = 298K
4. Convert 298K to °C.
298K-273 = 25C
5. Chemist Smith recorded a temperature of 65°C. What is the corresponding Kelvin temperature?
65C + 273 = 338K
6. Your experimental apparatus shows an increase of 2°C every minute. By how many Kelvin is the apparatus’s
temperature increasing?
2C + 273 = 275K
Kinetic Molecular Theory
7. What are the 4 assumptions of the KMT.
Gas particles have no mass
Gas particles are in constant random motion
Gas particles do not attract or repel each other
Gases all have the same Kinetic Energy if they have the same Temperature
8. The KMT is a theory that ____.
a. stands for kinetic motion tropism
c. discusses how gas particles stand still
b. discusses how gas particles act
d. proves the existence of gas
9. Which of the following is NOT part of the KMT?
a. Gas molecules move in a certain path.
c. Gas molecules do not lose energy when they collide.
b. Gas molecules collide elastically.
d. Gas molecules do not attract one another.
10. Which of the following IS part of the KMT?
a. Gas particles move on special paths.
c. Gas particles are relatively large particles.
b. Gas particles do not collide elastically.
d. Gas particles are in constant motion.
11. Which of the following definitions correctly defines diffusion?
a. The process by which gas particles travel
b. The slow dispersion of gas particles into the environment
c. The random spread of gas particles from high-pressure to low-pressure areas
d. The random spread of gas particles from low-pressure to high-pressure areas
12. Explain the relationship between particle motion, kinetic energy, and temperature?
As particle motion increases, the kinetic energy increases since KE measures the energy of motion.
Temperature measures the KE of a substance so if KE increases then the temperature will rise. Thus, all
three – particle motion, KE, and temperature are DIRECTLY related.
13. Label each of the following statements about the KMT as true (T) or false (F)
a.
b.
c.
d.
e.
Gas particles have no mass, that is why we cannot feel them as we move through air T
Gas particles move in random, fast motion. T
Gas particles are extremely attracted to one another and will congregate in one spot. F
Gas particles have no kinetic energy and thus we cannot measure the temperature of gases. F
The temperature and kinetic energy of gases are inversely related. F
Gay-Lussac’s Law *Remember to convert degrees Celsius to Kelvin
14. Gay-Lussac’s Law compares pressure and temperature. It looks like this:
a.
P1
 P2T2
T1
c. P1T1  P2T2
b.
P1 P2

T1 T2
d. P1T1 
P2T2
15. Pressure and temperature have a direct relationship. What does it mean to have a direct relationship?
A direct relationship means as one variable changes the other one changes in the same direction.
16. Compute the missing value: T1 = 322K; P1 = ?; T2 = 303K; P2 = 2.0atm
P1 = 2.125atm
17. A gas system has an initial temperature of 443.0K with the pressure unknown. When the temperature changes
to 1390K the pressure is found to be 7.77atm. What was the initial pressure in atmospheres?
P1 = 2.476atm
18. A gas system has initial pressure and temperature of 12.0atm and 27.9°C If the pressure changes to 3.74atm,
what will the resultant temperature be in °C?
T2 = -179.22 degrees C
The Mole: Avogadro’s Law & Molar Volume
19. If I have 1 dozen cookies, what number of cookies do I have?
12 cookies
20. If I have 1 mole of cookies, what number of cookies do I have?
6.02x10^23 cookies
21. 1 mole = how many particles?
6.02x10^23 particles
Directions: Read the following passage in order to complete questions 22 – 25.
In this course you will be learning about 6 laws that describe the unique properties of gases. The first you will
uncover connects back to last week’s homework on the mole. Avogadro's law is the first gas law you will be
defining. Avogadro’s law states that, under the same condition of temperature and pressure, equal volumes of
all gases contain the same number of particles. The law is named after Amedeo Avogadro who, in 1811,
hypothesized that two given samples of an ideal gas, of the same volume and at the
same temperature and pressure, contain the same number of particles. Thus, the number of particles in a
specific volume of ideal gas is independent of their particle size or the individual particle mass of the gas.
As an example, equal volumes of hydrogen and nitrogen contain the same number of particles when they are
at the same temperature and pressure. In practice, real gases show small deviations from the ideal behavior
and the law holds only approximately, but is still a useful approximation for scientists.
The molar volume is the volume occupied by one mole of a substance a given temperature and pressure.
Molar volume simply links Avogadro’s Law to the mole. 1 mole of every gas occupies the same volume, at
the same temperature and pressure. At STP (standard temperature and pressure), this volume is 22.4 liters.
Or in other words, the molar volume of a gas is 22.4 liters at STP (standard temperature and pressure). Thus,
1 mole of gas occupies 22.4 liters in volume at standard temperature and pressure.
22. What does Avogadro’s Law state?
Gases of the same volume and at the same pressure and temperature contain the same number of
particles.
23. If I have a specific volume of two different gases at standard temperature and pressure, do the gas samples
have the same number of particles?
Yes
24. If I have 1 mole of gas X at standard temperature and pressure, what is the volume of gas X?
22.4 liters
25. If I double the moles of gas X, what is its volume now?
44.8 liters
26. If I have 67.2 liters of gas X at standard temperature and pressure, how many moles of gas X do I have?
3 moles of gas X