# What is Boyle's law: Definition and 41 Discussions

Boyle's law, also referred to as the Boyle–Mariotte law, or Mariotte's law (especially in France), is an experimental gas law that describes how the pressure of a gas tends to decrease as the volume of the container increases. A modern statement of Boyle's law is:

The absolute pressure exerted by a given mass of an ideal gas is inversely proportional to the volume it occupies if the temperature and amount of gas remain unchanged within a closed system.

Mathematically, Boyle's law can be stated as:

or

where P is the pressure of the gas, V is the volume of the gas, and k is a constant.
The equation states that the product of pressure and volume is a constant for a given mass of confined gas and this holds as long as the temperature is constant. For comparing the same substance under two different sets of conditions, the law can be usefully expressed as:

P

1

V

1

=

P

2

V

2

.

{\displaystyle P_{1}V_{1}=P_{2}V_{2}.}
This equation shows that, as volume increases, the pressure of the gas decreases in proportion. Similarly, as volume decreases, the pressure of the gas increases. The law was named after chemist and physicist Robert Boyle, who published the original law in 1662.

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1. ### Percentage change in the density of a gas

Hi all, in this question i was asked to find the percentage change in the density, my approach was as following, first i find the change in volume due to putting the gas into the other vessel as: $$P_{1}V_{1}=P_{2}V_{2}\;\; → \;\;V_{2}=\frac{P_{1}}{P_{2}}V_{1}$$ now i use ...
2. ### How to calculate the leak rate based on pressure drop

I am currently working on a project trying to calculate leak rate and fluid loss from pressurised vessels filled with water over a time period of 30 minutes. So far I have used the Boyles Law which assumes that PV/T = constant which gets us P1 * V1 = P2 * V2 and PdV+VdP = 0 I formed this over to...
3. ### Engineering Find the volume of a gas using Boyle's law

Is this right go confused with the 37 degrees Q) pV = Constant pressure of a gas is ‘10’ (kPa) and the constant ‘37 degrees celcus’ = ‘0.6’, calculate the volume that the gas. pV = C C/p = V 0.6/10 = C V = 0.06
4. ### MHB Exploring Robert Boyle's Law: Pressure and Volume of CO2

Robert Boyle's law states that at constant temperature, the pressure of fixed amount ( i-e number of moles n) of gas varies inversely with its volume. Mathematically, it can be written as $p ∝ \frac1V$(at constant T and n) $\Rightarrow p = k_1 \times \frac1V$ where $k_1$is a proportionality...
5. ### Effect on Volume of a Change in the Pressure of Compressible Gas

Will the available Volume of oxygen gas for use of patients increase when the pressure decreases from 12.4 MPa to 500 KPa? Is using boyle's law the right way to calculate the available volume?
6. ### B Boyle's law vs the Venturi effect

So this is something I been thinking about. In venturi principle when a fluid or gas is moving across a tube when it is constricted the fluid has increased velocity. Because it in constriction the pressure goes down. But in Boyle law if volume is decreased the pressure goes up. So in the...
7. ### Boyle's Law and Applied pressure

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8. ### Calculating the Length of a Water Column in a Beaker

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9. ### Can a Self-Gravitating Gas Ball Simulate Stellar Formation Dynamics?

I have a simulation I'm trying out (for fun). A self-gravitating ball of gas, in deep space. (The sim uses a fixed-time-step for each iteration.) I'd like to use Boyles Ideal gas law, the force of gravity, and energy as internal heat. (I don't want to touch enthalpy unless I don't realize...
10. ### Boyle's law pressure calculation

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11. ### Pressure required to move a liquid

I have a container that measures 1 cubic foot and is full of water. I have another empty container that is 4.5 feet higher than the empty container. The full container has a fluid outlet on the bottom, and an air inlet on the top. A hose (1 inch diameter, 4.5 feet long) connects the fluid outlet...
12. ### Flow rate of air in discharging reservoir

If I have a tank of volume V, pressure P, and temperature T, what is the most effective way to determine the volume flow rate if I were to suddenly allow the air to discharge through a hose? My first thought was that I could use Boyle's Law to determine the compressed volume of air in the tank...
13. Z

### Air Hockey Calculation for Air Blowing System

Hello, Right now I'm doing a Final Year Project 1 which is Air Hockey. The different between our air hockey and normal air hockey are our air hockey is octagonal shape. but now I'm stuck at calculating the air pressure for the table. can you help us? again this is just a school project not...
14. ### IGCSE Physics Boyle's law question

Homework Statement The helium in the cylinder has a volume of 6.0 × 10^–3 m3^-1 (0.0060 m^3) and is at a pressure of 2.75 × 10^6 Pa. (i) The pressure of helium in each balloon is 1.1 × 10^5 Pa. The volume of helium in an inflated balloon is 3.0 × 10^–3 (0.0030 m3). The temperature of the...
15. ### How Do I Determine the Change in Entropy of the System?

Homework Statement Determine ΔSsys when 3.0 mol of an ideal gas at 25°C and 1 atm is heatedd to 125°C and expanded to 5 atm. Rationalize the sign of ΔSsys. Homework Equations State Function: dS = (dU)/T + (PdV)/T State Function for Entropy of Ideal Gas: dS = (CV,mdT)/T + (nRdV)/V Ideal gas...
16. ### What is the independent variable in Boyle's Law?

I asked my teacher, and I was told that volume is the independent variable, and that pressure is dependent. The textbook I'm using said the same thing. After looking up some graphs of the law, I found that both pressure and volume were used as independent variables. It seems counter-intuitive...
17. ### Confused about Boyle's Law, Charles' Law and the pressure Law?

In my textbook, it says that pV=C (Boyle's Law), V/T=C (Charle's Law) and that P/T=C (pressure Law). The problem is that I cannot see how the first two equations combine to give the last one. If I divide the first equation by the second, I get that pT=C, which certainly is not the same as the...
18. ### Boyle's law and constant temperature

Boyle's law states that the product of the pressure and the volume of a gas is Constant at a constant temperature, that means if pressure increase two times the volume decrease to half it's value "as long as the temperature is constant". How is the pressure increased and the temperature is kept...
19. ### Exploring the Relationship Between Boyle's Law and Plate Tectonics

I have been trying to find out of Boyle's Law and plate tectonics are in any way shape or form related. Are they? If they are not, is there a way I can relate their movement to physics?
20. ### Boyle's Law and collisions by the ideal gas molecules on the container

When we use Boyle's Law it means that as pressure increases the volume of the container would decrease. In my notes they stated that if I were to halve the volume there would be two times the number of collisions per second which implies that the force exerted is doubled. But why is this so? I...
21. ### Boyle's Law - Experiment Question

Hey guys, I was just wondering if you could help me on this quick question I have. Homework Statement A student does an experiment to investigate Boyle's Law by adding masses onto the bottom of an upside down syringe and measuring the length of the gas column in the syringe. Force is...
22. ### Refridgeration, Boyle's law or enthelpy of vaporization?

I've curious about how an air conditioner or refrigerator make's cold air. I've read two different descriptions how cold is "made", or how heat is removed from a system. Some descriptions I've read say that air conditioners use expanding gas in it's coils, hence the use of Boyle's law. Other...
23. ### Solve Boyle's Law Problem: Calculate Atmospheric Pressure

A narrow uniform glass tube contains air enclosed by a thread of mercury 15cm long. When the tube is held vertically, with the closed end at the bottom,the air column is 20.0cm long, but when it is held horizontally the air column is 24.0cm long. Calculate the atmospheric pressure. I...
24. ### Boyle's Law, does it hold true in a non finite container ?

If a gas will expand to fill the available space (container) does this still hold true if the "container" is the atmosphere? Assuming the gas(es) can escape (either in molecular or in subs - atoms) from the area around the Earth containing our atmosphere this means that the gas is not...
25. ### Understanding Boyle's Law: The Effect of Volume Increase at Constant Temperature

Effect of a volume increase at constant temperature: A constant temperature means that the average kinetic energy of the gas molecules remains unchanged. This in turn means that the rms speed of the molecules, u, is unchanged. If the volume is increased, however, the molecules must move a longer...
26. ### Solving Boyle's Law Question: Max No. of Balloons to Inflate

Hi, I was working through a past exam paper when I came across a Boyle's Law question in which the answer to the second part confused me. I will write the question, part one and its solution and the second part. Here is the question : A rigid cylinder contains 0.08 m^3 of helium gas at a...
27. ### General Application of Boyle's Law

Hello, I am Year 10 student and would like to get help on the question below based on Boyle's Law. A piston with a block of mass 120 grams placed on it traps 200cm³ of air in a container. When the block is removed, the volume becomes 250cm³. Find the mass of the piston. In the question...
28. ### Boyle's Law [mmHg]: Solving Atmospheric Pressure with a Mercury Barometer

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29. ### Apparently easy but super frustrating question about Boyle's Law

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30. ### Boyle's Law: Calculating Balloon Size at Surface After 40 m Descent

Homework Statement A diver dives to a depth of 40 m in fresh water where he releases a toy balloon of volume 10 cm^3. What will be the size of the balloon when it reaches the surface? (The pressure increass at a rate of 1 atmosphere for every 10 m descent in fresh water) Homework...
31. ### Ideal gas equation and boyle's law

The mass of a hot-air balloon and its occupants is 289 kg (excluding the hot air inside the balloon). The air outside the balloon has a pressure of 1.01 x 105 Pa and a density of 1.29 kg/m3. To lift off, the air inside the balloon is heated. The volume of the heated balloon is 890 m3. The...
32. ### Solving for Depth in Boyle's Law: Barometer Tube Submerged in Water

Homework Statement An empty barometer tube,1m long is lowered vertically, mouth downwards, into a tank of water. what will be the depth of the top of the tube when the water has risen 20cm inside the tube?(atmospheric pressure may be assumed to be equal to 10.4m head of water) Homework...
33. ### Boyle's Law: J-Tube Experiments & Air/Water Effects

Hi, I have a question to ask... How would the presence of air bubbles or water in mercury affect the results in a "J-tube" experiment?
34. ### Water Pipe Boyle's Law Mystery.

This is a very curious situation. I have a large water tank on the top of a hill. It supplies a gravity fed water system that works fine. There is an under ground pipe with one end A in the bottom of the tank. The other end E is about 80 feet below A, and has a faucet. None of the pipe is...
35. ### Calculating Cross-Sectional Area Using Boyle's Law and a Mercury Barometer

A mercury barometer reads 75 cm. Now 3 cc of atmospheric air is introduced into the tube. The mercury falls to a height of 65 cm and the length of air column above mercury is found to be 15 cm. Calculate the cross sectional area of the tube. This question in my book has been solved by boyle's...
36. ### Boyle's law doesn't work here?

Sir, I have a have a doubt in the following problem: # A volume V of air saturated with water vapour exerts a pressure P. If the volume is made V/2 isothermally, what will be the final pressure? I solved it using Boyle's law but that answer which is "2P" doesn't agree with the answer...
37. ### How Do You Calculate Temperature and Pressure in Boyle's Law Problems?

Hi Everyone, first semester Physics student here and we are working on a tough lab this week, having to do with Boyle's Law...argghh! :cry: Anyways, here is my problem, and trying to work through it to obtain the correct answer...but it is stumping me! The question as follows: 1...
38. ### Boyle's law and pressure problem

According to boyle's law, P1V1=P2V2 (without temp. change) right? Therefore when 10cm^3 of oxygen is compresssed into a 5 cm^3 container , the pressure would double right? I believe that the pressure the molecules exerts on the container is due to the force that the molecules exert when they...
39. ### Calculating Pressure with Boyle's Law: 38 lbs of Books on 0.45 in^2 Syringe

So i looked up Boyle's and it said PV = C P= pressure V= Volume C= constant so my question is Suppose 38 pounds of books were balanced on a syringe plunger with a cross-section area of 0.45 in^2? A) how much pressure would just the books exert on the trapped air sample...
40. ### Understanding Boyle's Law and Its Impact on Experiments and Cooking Techniques

Hello everyone! I have some questions here to ask... I hope anyone could help me here. Here are the following. 1. How would the presence of air bubbles or water in mercury affect the results in a "J-tube" experiment? 2. Why does food cook faster in a pressure cooker than in an...
41. ### How Do Absolute Pressure and Gauge Pressure Differ?

Hello guys, I got some problems again. Will you be able to help me? What is the difference between the absolute pressure and gauge presure? Why is the absolute pressure plotted vs the length of the column of the trapped air instead of the volume of trapped air in the J-Tube?