Chemistry
Unit 2
Name ________________________
Period ___ Date _______________
Worksheet # 5: Pressure-Number of Particles
On each of the problems below, start with the given P,V,T or n; then make a decision as to how a
change in P, V, T, or n will affect the starting quantity, and then multiply by the appropriate factor.
1 atm = 760 mmHg = 101.3 kPa
1. A closed flask of air 0.250 L contains 5 units of particles. The pressure probe on the flask reads 93
kPa. A student uses a syringe to add an additional 3 units of particles. Find the new pressure inside
the flask.
P
T
V
n
Initial
Final
Effect
a. What variables are constant? ( NOT CHANGING!) ___________ & ___________
b. Solve for the final value.
c. Draw a particle picture to illustrate the behavior of the particles.
2. A container has a pressure of 720mmHg and contains 8 units of particles. If the pressure changes to
800 mmHg, how many units of particles do you have?
P
T
V
n
Initial
Final
Effect
a. What variables are constant? ( NOT CHANGING!) ___________ & ___________
b. Solve for the final value.
c. Draw a particle picture to illustrate the behavior of the particles.
3. A plane’s pressure is 1.3 atm on the ground and contains 17 units of particles. If the units of
particles changes to 21, what is the pressure?
P
T
V
n
Initial
Final
Effect
a. What variables are constant? ( NOT CHANGING!) ___________ & ___________
b. Solve for the final value.
c. Draw a particle picture to illustrate the behavior of the particles.
4. A sub has a pressure of 756 mmHg and contains 1.9 units of particles. If the unit of particles changes
to 25, what is the new pressure?
P
T
V
n
Initial
Final
Effect
a. What variables are constant? ( NOT CHANGING!) ___________ & ___________
b. Solve for the final value.
c. Draw a particle picture to illustrate the behavior of the particles.
5. A perfume bottle contains 14 units of particles and a pressure of 805 mmHg. Some of the perfume
is released and the pressure is now 789 mmHg, how many units of perfume remains?
P
T
V
n
Initial
Final
Effect
a. What variables are constant? ( NOT CHANGING!) ___________ & ___________
b. Solve for the final value.
c. Draw a particle picture to illustrate the behavior of the particles.
6. A tennis ball has a pressure of 879 mmHg and 3 units of particles. The ball goes flat and now has a
pressure of 760 mmHg. How many units of particles remains in the ball?
P
T
V
n
Initial
Final
Effect
a. What variables are constant? ( NOT CHANGING!) ___________ & ___________
b. Solve for the final value.
c. Draw a particle picture to illustrate the behavior of the particles.
7. Tires can explode if overinflated. A tire has 6 units of particles and a pressure of 789 mmHg. If 2
more units of particles is added, what is the new pressure?
P
T
V
n
Initial
Final
Effect
a. What variables are constant? ( NOT CHANGING!) ___________ & ___________
b. Solve for the final value.
c. Draw a particle picture to illustrate the behavior of the particles.