Tuesday, February 3, 2026

Chemistry - Practice Problems on Gas Laws

Boyle’s Law (P1V1 = P2V2)

1. A sample of oxygen gas occupies 10.0 L at a pressure of 101.3 kPa. What will its volume be if the pressure is increased to 202.6 kPa?

2. A gas has a volume of 500 mL at 0.95 atm. What is the pressure (in atm) if the volume is compressed to 125 mL?

3. A balloon is filled with 2.5 L of air at sea level (101.3 kPa). If it rises to 75.0 kPa, what is the new volume? 

4. If a gas at 3.0 atm is compressed from 4.0 L to 1.5 L, what is the final pressure?

5. A syringe contains 60.0 mL of gas at 100.0 kPa. To what volume must the gas be expanded to reach 40.0 kPa?

6. A diver exhales a 20.0 mL bubble at a depth where the pressure is 3.5 atm. What is the volume of the bubble when it reaches the surface (1.0 atm)?

7. A 2.0 L tank of helium is at a pressure of 15,000 kPa. If this gas is transferred to a 12.0 L tank, what is the new pressure? 

8. A gas sample at 800 mmHg occupies 300 mL. If the pressure is reduced to 600 mmHg, what is the new volume? 

9. A 5.0 L container holds nitrogen at 2.5 atm. If the volume is changed so that the pressure becomes 1.25 atm, what is the new volume? 

10. If the volume of a gas is tripled, what happens to the pressure? Show the mathematical relationship.

Charles’ Law (V1/T1 = V2/T2)

11. A sample of neon gas occupies 2.0 L at 293 K. What will be its volume at 350 K?

12. A balloon has a volume of 1.5 L at 25°C. What is its volume if placed in a freezer at -10°C?

13. A gas occupies 5.0 L at 100°C. At what temperature (in °C) will the volume be 2.5 L?

14. If a 450 mL sample of gas at 273 K is heated to 546 K, what is the new volume?

15. A container holds 12.0 L of gas at 50°C. If the volume expands to 18.0 L, what is the new temperature in Celsius?

16. A gas at 20°C has a volume of 0.75 L. To what temperature must it be heated to double its volume?

17. A sample of hydrogen occupies 100 mL at 27°C. What is its volume at 127°C?

18. At 0°C, a gas has a volume of 25.0 L. If the volume decreases to 20.0 L, what is the new temperature in Kelvin?

19. A 2.2 L balloon at 300 K is moved to an environment at 250 K. What is the new volume?

20. A gas sample occupies 8.0 L at 27°C. What volume will it occupy at 227°C?

Ideal Gas Law (PV = nRT)

21. How many moles of gas are in a 5.0 L flask at 200 kPa and 30°C?

22. What is the pressure (in kPa) exerted by 0.50 moles of CO2 in a 10.0 L container at 25°C?

23. What volume will 2.5 moles of nitrogen occupy at 1.2 atm and 310 K?

24. A 2.0 L bottle contains 0.40 moles of gas at 5.0 atm. What is the temperature in Kelvin?

25. Find the mass of oxygen (O2) in a 15.0 L tank at 150 kPa and 27°C. (Molar mass O2 = 32.0 g/mol).

26. A 500 mL flask is filled with 0.15 moles of helium at 22°C. What is the pressure in atm?

27. Calculate the moles of gas in a 25.0 L container at STP (273 K and 101.3 kPa).

28. What is the temperature (in °C) of 1.2 moles of gas that occupies 20.0 L at 1.5 atm?

29. A gas sample has a mass of 10.0 g and occupies 4.0 L at 2.0 atm and 300 K. What is its molar mass?

30. How many moles of gas are in a 0.25 L container at 10.0 kPa and 150 K?

//

Answer Key

  1. 5.0 L

  2. 3.8 atm

  3. 3.38 L

  4. 8.0 atm

  5. 150.0 mL

  6. 70.0 mL

  7. 2,500 kPa

  8. 400 mL

  9. 10.0 L

  10. P2 = 1/3 P1

  11. 2.39 L

  12. 1.32 L

  13. -86.5°C

  14. 900 mL

  15. 211.5°C

  16. 313°C

  17. 133.3 mL

  18. 218.4 K

  19. 1.83 L

  20. 13.3 L

  21. 0.40 mol

  22. 123.9 kPa

  23. 53.0 L

  24. 304.5 K

  25. 28.9 g

  26. 7.26 atm

  27. 1.11 mol

  28. 31.6°C

  29. 30.8 g/mol

  30. 0.002 mol 

Monday, February 3, 2025

New Worksheet - Physics - Sound Intensity

Problem 1
An amplifier takes a 20 decibel sound and turns it into a 60 decibel sound. How many times larger is the intensity of the sound waves coming out of the amplifier as compared to the intensity of the sound waves going into the amplifier?
Answer: ________________

Problem 2
An amplifier takes a 35 decibel sound and turns it into an 85 decibel sound. How many times larger is the intensity of the sound waves coming out of the amplifier as compared to the intensity of the sound waves going into the amplifier?
Answer: ________________

Problem 3
An amplifier takes a 10 decibel sound and turns it into a 70 decibel sound. How many times larger is the intensity of the sound waves coming out of the amplifier as compared to the intensity of the sound waves going into the amplifier?
Answer: ________________

Problem 4
An amplifier takes a 57 decibel sound and turns it into a 87 decibel sound.  How many times larger is the intensity of the sound waves coming out of the amplifier as compared to the intensity of the sound waves going into the amplifier?
Answer: ________________

Friday, January 31, 2025

Classes I Teach


I have taught each of the classes listed below at least once (many of them I have taught multiple times). 
  • ACT Test Preparation
  • Algebra 1
  • Ancient Civilizations (7th grade - one semester)
  • Applied Engineering (7th grade)
  • Astronomy (7th grade - one semester)
  • Basic Auto Mechanics (high school)
  • Chemistry (high school)
  • Chemistry Basics (7th grade - one semester)
  • Cultural World Geography (middle school)
  • Cultural World Geography (high school)
  • Earth and Life Science (7th grade - one semester)
  • English Literature - Emma by Jane Austen for high school (8 weeks)
  • English Literature - Pride and Prejudice by Jane Austen for high school (8 weeks) 
  • English Literature - Sense and Sensibility by Jane Austen - English Literature (8 weeks) 
  • English Literature - The Hobbit by J. R. R. Tolkien for high school (8 weeks)
  • English Literature - The Fellowship of the Ring by J. R. R. Tolkien for high school (12 weeks)
  • English Literature - The Two Towers by J. R. R. Tolkien for high school (12 weeks)
  • English Literature - The Return of the King by J. R. R. Tolkien for high school (12 weeks)
  • European History 5th-19th centuries (7th grade - one semester)
  • General Science (7th grade)
  • Grammar and Writing (7th grade)
  • Holst: The Planets (6th-9th grade) (4 weeks)
  • Intro to C# (high school)
  • Jekyll, Hyde, and Scrooge, and the 1800s (middle school - one semester)
  • Jekyll, Hyde, and Scrooge, and the 1800s (high school - one semester)
  • J.R.R. Tolkien, C.S. Lewis, and Their World from 1900 through 1939 (middle school) 
  • J.R.R. Tolkien, C.S. Lewis, and Their World from 1900 through 1939 (high school) 
  • Lego Robotics 1 (high school)
  • Lego Robotics 2 (high school)
  • Physical Science (high school)
  • Physics (high school)
  • SAT Test Preparation
  • The Scarlet Pimpernel and the 1700s (middle school - one semester) 
  • The Scarlet Pimpernel and the 1700s (high school - one semester) 
  • Sergei Prokofiev: Peter and the Wolf - A Musical Journey (6th-9th grade) (4 weeks)
  • Western Civilization 1 (high school)
  • Western Civilization 2 (high school)

Related Posts Plugin for WordPress, Blogger...