Gasses - Moles vs. VolumeHASPI Medical Chemistry

Background/Introduction You breathe in and out, in and out, about 25,000 times in a normal day. What is it that allows for each breath to enter your lungs? What are some health concerns that can affect your ability to breathe?

You have a muscle below your lungs called the diaphragm. This U-shaped muscle moves downward when it contracts. This increase of volume inside your lungs allows air to rush in through your mouth. This is caused because the pressure inside the lungs changes when the volume inside the lungs changes. When your lungs change in volume more moles of air molecules are able to enter the lungs.

Inside your lungs this increase in volume allows the alveoli (small air sacs) to expand to allow the air to come into contact with your blood vessels so that Oxygen can be exchanged for Carbon Dioxide. Respiratory diseases are the third leading cause of death in the united states, killing over 140,000 people each year. Caring for these patients are a key focus in a hospital. In fact, one career you could consider is a respiratory therapist, which is a person who just works with each patient to ensure lung health.

Asthma causes inflammation of the airways. Within your lungs any inflammation reduces your lung volume. COPD – Chronic obsructive pulmonary disease – causes difficuluty exhaling normally. If you cannot exhale normally, you are unable to inhale normally because you don’t have the change in volume needed to allow air to rush in. Emphysema causes lung damage that can trap air in the lungs. This means that you are not able to increase and decrease the lung volume significantly and it causes trouble breathing and decreased oxygen levels. Cystic fibrosis is a genetic condition that makes it hard to clear out the mucus that accumulates in your lungs. This can cause infections, and it reduces the volume of the lungs available for air flow. All of these diseases alter the volume of the lungs so that breathing, and therefore gas exchange, is not as efficient as it could be.

Materials AvailableBalloons, lung model, Vernier Probeware

Conceptual Questions1. What happens to the moles of gas in the lungs when you expand the volume by contracting the

diaphragm? 2. What happens to the moles of gas in the lungs when you reduce the volume by relaxing the

diaphragm. 3. Hiccups are caused by diaphragm spasms. Explain what causes the feeling and sound of hiccups.4. Choose one of the diseases above and explain how it affects both moles and volume of the lungs.

Name(s): Period: Date:

http://www.singintune.org/voice-production.html

Gasses - Volume vs. Pressure HASPI Medical Chemistry

Background/IntroductionHeart disease is the leading cause of death in the U.S. with over half a million deaths per year. When someone has a heart attack or angina (chest pain) and goes to the hospital one of the medical treatments they might undergo is cardiac catheterization.

This procedure allows doctors to diagnose and often treat heart conditions. A catheter is a tube that can be inserted into the body, and in cardiac catheterization this tube is inserted into a blood vessel, usually in the groin, and passes through the bloodstream until it reaches the heart.

The tube can be used to insert dye that shows up in a fluoroscope, which is a machine which can take videos similar to x-rays. The dye allows for contrast images in real time so that doctors can see where the blood is pumping – which can also reveal where any blockage can occur. A heart attack is usually caused when a clot gets caught in a narrowed artery that brings blood to the heart muscles. Without blood brought directly to the heart, the muscle can no longer pump the rest of the blood throughout the body. This kind of heart attack is called a myocardial infarction or MI.

If it is determined that a coronary artery has been blocked or narrowed, an angioplasty can help to widen or open the vessel. In an angioplasty a small balloon is inflated at the end of the tube once the catheter reaches the vessel around the heart where the blockage has occurred. By increasing the volume of the balloon, the pressure changes and is able to gently push against the walls of the artery so that it is opened up again and blood can move freely. Doctors use a syringe at the end of the catheter to alter the volume of the balloon.

If the artery is not sturdy after this procedure, a tiny mesh tube called a stent similar to a spring can be placed inside of the vessel to keep it open and allow the blood to flow.

Over 1 million cardiac catheterizations are performed every year in the U.S. Some are angioplasties, however other cardiac catheterization procedures include placing pacemakers or internal defibrillators, measurement of blood flow and oxygenation throughout the heart and vessels, biopsy and minor repairs. This is a safe alternative to surgery as it allows the heart to continue its job, does not stop or slow the heart and does not require the chest to be opened, significantly reducing the amount of risk.

Materials available Syringe, balloons, clear tubing

Conceptual Questions1. How does changing the volume of the syringe alter the pressure in the balloon?2. Would the doctor want to increase or decrese the syringe volume in order to increase the pressure

of the balloon on the vessel? Why?3. Come up with another use for this kind of technique and describe it here.

Name(s): Period: Date:

http://www.nawalokaheartcentre.com/angiography

http://bme240.eng.uci.edu/students/08s/dchalyan/index.html

Gasses - Pressure vs. MolesHASPI Medical Chemistry

Background/IntroductionSome diseases cause the oxygen levels in the blood to dip. Chronic obstructive pulmonary disorder (COPD) is one disease that causes this because less air can get into the lungs.

In order to help these patients increase their oxygen levels, they can have oxygen gas delivered by nasal cannula. This is a small tube of oxygen that goes to the nose so that when you breathe in there is extra oxygen available, increasing the amount of oxygen in the lungs.

Since the air around us is only 21% oxygen gas, adding extra oxygen to each breath allows more oxygen to reach the blood stream. Most of us are able to saturate our blood with oxygen by breathing normal air so adding oxygen in this way does not help a person unless they are having reduced oxygen levels in the

first place.

In order for the oxygen gas to be stored it must be compressed into tanks. These tanks have a fixed volume, however, by changing the pressure more moles of oxygen can be added to the tank. The amount of oxygen can vary depending on the volume of the container and the pressure the container is under. The valve on the tank can be set to deliver a certain amount of oxygen per hour.

Many patients need just 2L/hour which is about .0893moles of gas per hour. Think about the normal 2L bottle of soda you can buy in the store. Imagine if

a patient had to get a new 2L bottle of oxygen gas every hour. Not only would that be difficult to store and carry around, a non-pressurized oxygen would be difficult to get through that little tube to the patient’s nose. By pressurizing oxygen, a patient can carry a small bottle filled with 5-10 hours worth of oxygen at a time so they need only one bottle when they leave the house.

The most common tanks are size D, which has a capacity for 19.0moles of O2 at 2000.psi, and size E which has a capacity for 30.4 moles of O2 at 2000.psi. Thankfully, these are a great resource for patients so that they can remain well oxygenated at home or on the go, and they reduce their need for emergency medical care.

Materials available Ball pump with pressure gauge, 2L bottles with pumps and a balance

Conceptual Questions1. 1 mole of oxygen gas takes up 22.4L in normal conditions.

a. How many Liters of gas can come out of a size D tank?b. How many Liters of gas can come out of a size E tank?

2. How many hours can a size E tank provide air for a patient who takes 2L an hour?3. How many hours can a size E tank provide air for a patient who takes 4 L an hour?4. If a size E tank is originally at 2000.psi, what should the pressure read when it is half full?

Name(s): Period: Date:

http://www.politedissent.com/archives/105

http://www.oemeyer.com/homemedical/respiratory-therapy-oxygen

Gasses - Volume vs. TemperatureHASPI Medical Chemistry

Background/IntroductionWhen gasses heat up they will take up more space. Just think about a cake in the oven. First you whip together all of the ingredients, then you put it in the oven. What causes it to rise?

Most cakes have baking soda or baking powder inside of them, which react to form gas. As the cake heats up the gas bubbles expand and the cake rises. Once the other ingredients cook they hold their form, so when you pull the cake out of the oven it stays fluffy. If you look closely as you bite into cake you will notice that it’s full of tiny holes, the air pockets that expanded as it heated.

Breads have yeast which eat sugars in the dough and make bubbles of air. This is why bread has to rise a few times at low temperatures so that the yeast can make their bubbles. Once you really cook the bread at the end the bubbles expand and the heat kills of the yeast.

Have you ever enjoyed an ice cold soda but then felt like you really had to burp? This also has to do with the heating of the carbon dioxide in the stomach. First

of all, when the soda warms up and is mixed around by your stomach it comes out of solution to become gas bubbles. As the gas bubbles warm up and more gas comes out of the soda solution they get bigger, pushing on your esophagus, causing it to open up and let the air out.

Heartburn can be caused when you burp excessively, because some of your stomach acid may go into the esophagus and cause it to burn. When the small muscle at the top of the stomach has trouble closing this can also cause heartburn. When people have heartburn constantly, which is called acid reflux, the acids can burn the esophagus and require medical treatment.

ExperimentErlenmeyer flask, balloon, hot plate, ice bath,

Conceptual Questions1. What would happen to a cake if there was not much gas in the batter?2. What would happen to a cake or bread if you mixed and mixed and mixed it before you baked it?3. What is one thing a patient can change to reduce heartburn?

Name(s): Period: Date:

http://www.joshgitalis.com/a-simple-solution-to-reflux-bloating-gas-and-burping/

http://www.weekendbakery.com/posts/san-francisco-style-sourdough-

http://www.sweetgirlconfections.com/2010/08/23/sweet-alchemy/

Gasses - Pressure vs. TemperatureHASPI Medical Chemistry

Background/IntroductionMany items used in a hospital or lab are incinerated after use because they are contaminated by using them on patients, however many items can be sterilized and used over and over again, or sterilized before they are disposed of to keep contaminated items out of the landfills. An autoclave is a device used to sterilize medical or lab items under high temperature and pressure.

An autoclave works similarly to a pressure cooker. Once it is sealed, the temperature is increased. In a sealed vessel, a temperature increase also changes the pressure. This pressure change allows the water at the bottom to boil at a higher temperature – around 121°C. A valve at the top releases some air once the pressure exceeds 30 psi to ensure that the container doesn’t explode, however 15psi is enough to achieve the boiling point of 121°C. This superheated steam is able to kill off any microorganism it comes into contact with. Although most organisms are killed simply with boiling

water, there are still some that can remain. Autoclaves are hot enough to kill spores such as tetanus as long as they are exposed to heat for at least 12 minutes.

Once the cycle is complete the valve has to let out some of the gas slowly until the internal pressure equals the atmospheric pressure and it’s safe to open the lid. To ensure that everything reached the proper temperature, a special tape or packaging can be used that changes color once it reaches a certain temperature. This ensures that all of the items inside of the autoclave were hot enough to sterilize them.

Many autoclaves are much more advanced than this, however they all work on the premise of hot steam under pressure in order to kill off spores and other microorganisms. Thankfully this has significantly reduced the risk associated with surgery and other medical procedures by eliminating concerns of contamination.

ExperimentMicrowave, Ziplocks with water vapor, Hot & Cold water bath, Vernier Probeware, sealed Erlenmeyer flask

Conceptual Questions1. If heat is added to a sealed container, what will happen to the pressure?2. If a sealed container is cooled, what do you expect to happen to the container inside?3. When using a small propane cannister with a camping stove, sometimes frost will form on the

outside of the cannister. Use what you have learned about the relationship between pressure and temperature to explain this phenomenon.

Name(s): Period: Date:

http://www.marketizer.com/articles/how-does-an-autoclave-work-2574125.htm

Tetanus Sporeshttp://

www.humanillnesses.com/original/T-Ty/Tetanus.html

References – Pressure vs. Temperaturehttp://www.epa.gov/osw/nonhaz/industrial/medical/mwfaqs.htm http://www.who.int/water_sanitation_health/medicalwaste/emergmedwaste/en/http://www.explainthatstuff.com/autoclaves.html http://www.marketizer.com/articles/how-does-an-autoclave-work-2574125.htm http://generalbacteriology.weebly.com/sterilization-and-disinfection.html

References – Moles vs. Volumehttp://www.webmd.com/lung/lung-diseases-overviewhttp://www.nlm.nih.gov/medlineplus/lungdiseases.html

References – Pressure vs. Moleshttp://www.pioneeroxygen.com/portableo2.phphttp://www.tri-medinc.com/page12.htmhttp://www.thoracic.org/clinical/copd-guidelines/for-patients/why-do-i-need-oxygen-therapy.php

References – Volume vs pressurehttp://www.nhlbi.nih.gov/health/health-topics/topics/cath/whoneedshttp://www.cdc.gov/nchs/fastats/leading-causes-of-death.htm http://emedicine.medscape.com/article/1894124-overview