# Examples of Boyle's law in real life

### Examples of Boyle's Law in Reality:

Boyle's law state that the volume of a given mass of a gas is inversely proportional to its pressure, provided the temperature remains constant. This law was formulated by an English scientist named Robert Boyle in 1662. However, it may also be referred to as Boyle-Mariotte law or Mariotte's law.

Instances of Boyle's law are often seen around us. In fact, the mechanism of breathing is a function of Boyle's law. Below are examples of Boyle's law in real life:

#### 1. Opening a bottle of soda

Boyle's law is typically observed when a bottle of soda is opened. Recall that when sealed, the bottle of soda contains a gas within it, and that's carbon (IV) oxide or CO2. This gas is pressurized, and it remains within the bottle due to its small volume. For this reason, the CO2 has little space to move about, and this is just within the sealed bottle of soda.

When the bottle is opened, and depending on how it is opened, the COis released at varying speed. For instance, if the bottle of soda is vigorously shaken and opened suddenly, the CO2 rushes out with the liquid, hence a foamy substance fizzes up and spill over, and perhaps making a mess of our body or clothes. This happens because the pressurized COmixes up with the liquid when shaken up vigorously. The sudden opening of the bottle rapidly increases the volume of COexposure, thus making it fizz out immediately.

You can read on the physical and chemical properties of acid here.

Meanwhile, understand that one can gently allow the CO2 gas escape from the bottle if the cork is opened slowly. When this is done, the pressure of gas within the bottle gradually decreases while the volume increases simultaneously, which is in accordance with Boyle's law.​​​​​

#### 2. Use of a syringe

Boyle's law comes into play when a syringe is used. A syringe is a medical equipment utilized in the insertion of fluid into the body. It is also useful in obtaining fluid from the body system.

Parts of a syringe are the barrel, plunger, hub and needle. The barrel may contain fluid depending on its usage, while the plunger functions by increasing or decreasing the volume of the barrel whenever it is pulled up or down.

When the plunger is pulled up, the volume of the barrel increases and its pressure decreases. When this happens, fluid is sucked into the barrel through the needle and hub. This simple process explains how fluid is taken from the human body into a syringe.

When the plunger is pulled down, the volume within the barrel decreases while its pressure simultaneously increases. Through this process, fluid present inside the barrel is forced out. This is how fluid is passed into the body.

If a gas is present inside the barrel of a syringe (instead of a liquid), the same process will occur, and this is in accordance in Boyle's law. Meanwhile, understand that the bicycle pump works in a similar way as the syringe.

#### 3. Filling of balloons

The filling of balloons is a popular activity carried out by kids; and interestingly, Boyle's law is seen during the process.

Before air is blown into a balloon, it typically has a low pressure and large volume within it. For this reason, the balloon remains deflated, and one can easily squeeze it since it contains insufficient air.

When air is blown into the balloon, the empty space (volume) within it is reduced as air fills it. The pressure within the balloon increases, and due to its soft and elastic nature, it begins to expand. If air is continually blown into it, the spaces or volume within the balloon may become filled up. If this continues, the balloon may eventually burst from the increased pressure.

The balloon ruptures due to the lightness of its material, its elastic nature, the increased pressure and decreased volume (since it has been replaced by air).

#### 4. Breathing in humans

Breathing involves a process of inhalation and exhalation. During inhalation, the diaphragm contracts, and so does the internal intercostal muscles. Also, the rib cage expands. This process increases the volume of the thoracic cage and decreases its pressure, allowing in air through the nostrils into the lungs.

You can read on bones of the human skeleton here.

During the process of exhalation, the reverse happens, bringing about a decrease in the volume of the thoracic cage while its pressure increases. This is in accordance with Boyle's law as air rushes out from the lungs through the nostrils.

#### 5. Inflating and deflating tyres

An inflated tyre contains air, and this leaves little space (or decreased volume) within the tubes of the tyre. At the same time, the air pressure is increased within the tyre, giving rise to its pumped and rigid shape. This process obeys Boyle's law.

When a tyre is deflated, air leaves the tyre tubes. The tyre lacks proper shape and strength, thus making vehicular movement difficult. Meanwhile, understand that the tyre was able to become deflated due to an increased air pressure already present within it. Therefore, this air pressure is released outwards if there is an external puncture to the tyre tubes.

Meanwhile, understand that the deflation process (net movement of air out of the tyres) results from a reduced pressure within the tyre alongside its increased volume. This inverse relationship between pressure and volume is in conformity with Boyle's law

#### 6. Use of aerosols

Aerosols comprises spray paints, deodorants, perfumes, insecticides and the likes. Within its container, there are usually two components. These are the primary liquid product, for instance, the perfume, paint or an insecticide chemical, and a highly pressurized sealed gas which had become a solution.

On pressing the nozzle of the aerosol, the seal on the pressurized gas is opened, reducing its pressure in the process. On leaving the seal, the volume occupied by the gas increases as the aerosol moves out to a region of lesser pressure. This is a function of Boyle's law, and the net diffusion is felt through the scent of the aerosol, especially if it's a perfume or an insecticide.

#### 7. Deep water diving (scuba diving)

As the name implies, deep water diving requires the diver to dive deep inside a water body such as a river, sea or ocean. Such diver must take caution when going deep into the water, as well as their ascension upwards. If this is done wrongly, they could suffer a decompression sickness (also referred to as 'the bends'), and this happens to be a life-threatening condition.

In scuba diving, the deeper the diver goes, the more an increase in his/her body pressure, and a consequent decrease in the volume occupied by nitrogen gas. This implies that more nitrogen gas will enter into the diver's blood and body fluids. This is in accordance with Boyle's law, and the reverse happens whenever the driver ascend to the top of the water body.

You can read on red blood cells and hemoglobin here.

Now, the major challenge during deep water diving is the rate at which the diver ascend towards the top of the water. If this ascension is rapid, the nitrogen gas inside the diver's blood will also expand rapidly (that is, a sudden increase in volume), and this is dangerous. This is so because the pressure reduces suddenly also, and the nitrogen bubbles in the blood and body fluids begin to expand and return to their normal volume rapidly, which can result to a foamy blood. This process can also cause the blood capillaries to rupture, including the bladder cells and other cell membranes. This results into an expansion of the spaces between the divers joint, which is indeed a very painful experience. These joint pains are called 'the bends'. This explains a similar process why deep-water fish die when they are brought to the water surface.

If the diver ascends slowly in scuba diving, nitrogen gas molecules will expand slowly until they regain their normal volume without causing problems to the diver. This process of gradually reducing the pressure of nitrogen in the blood is termed depressurization, and it should be slow, not rapid.

This volume and pressure relationship of blood nitrogen encountered in scuba diving is a function of Boyle's law.

Similar to skuba diving, this law is supported by the air bubbles blown out by a diver. These bubbles are seen to expand in size as they rise upward, and this is due to their reducing pressure and increasing volume.

Other real life examples of Boyle's law are observed in the following:

• Storage of gas

• Space and space suits

• Air bubbles

• Fire extinguisher

• Internal combustion engine