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Monday, April 16, 2007 Gastric pains

Have you ever had gastric pains? Have you ever wondered what gastric pains is? Have you ever known where did gastric pains come from? Do you know what the foods you can and cannot eat are? Do you know how to test on them?

What are gastric pains?
Gastric problems share similar symptoms but may have different causes, such as impaired motility (the process by which food moves through the digestive system), too much stomach acid, or an infection. Tests for the presence of bacteria called H. pylori are available and strongly recommended for anyone who is being treated for an ulcer.
Gastric problems can be difficult to diagnose and often persist or recur without proper treatment. In order to properly assess your situation, your doctor will need a thorough and precise description of your symptoms, when they occur, how severe they are, what you ate beforehand and so on.

How do we check on the foods we can and cannot eat?
We use indicators to check on acids and alkali. In this case, we use natural indicators.

What has acids and alkali got to do with gastric pains?
There are some foods that taste sour, others that taste sweet, and some that are apparently neutral in taste. Certain foods contain acids that are taken in by the body economy; other foods contain acids that are not easily digested by the body. The latter types of acids are even unwholesome, because the body must treat them as waste, and their elimination may cause irritation or inflammation in the cells of the organs through which they must be eliminated.
The latter acids, those that are classed as unwholesome, are oxalic acid, tannic acid, benzoic acid and uric acid. The wholesome acids are citric acid, malic acid and tartaric acid.
The common foods that contain the wholesome acids are: oranges, grapefruits, pineapples, apples, peaches and other seeded fruits. Tartaric acid is found in grapes, pineapples, potatoes, carrots and endive.

What are acids and alkalis?

Acids:
Acids turn blue litmus paper red. Some examples are vinegar and lemon. Acids are generally sour and produce a stinging feeling, particularly strong acids. Acids often give food a sour, sharp flavor (lemon juice) and they can also be helpful, such as the acid in your stomach. Strong acids, such as battery acid can burn your skin.
It is traditionally considered any chemical compounds that when dissolved in water, gives a pH less than 7.0. It is a substance that produces hydrogen ions as the only positive ions when it is dissolved in water. [Usually words that end with “acid” is acids]
Alkali:
Alkali turns red litmus paper blue. Some examples are baking soda and shower foam. Alkalis solutions are slippery or soapy to the touch, caustic and bitter. Weak bases such as baking soda can be helpful to settle upset stomachs. Strong bases, such as
lye, can burn your skin.
Alkali is a substance that produces hydroxide ions as the only negative ions when it is dissolved in water. [usually words that end with “hydroxide” is alkalis]
Acids and alkalis only show their properties when dissolved in water. The reason is that when an acid or alkali is dissolved in water, hydrogen ions, are released giving the acid its characteristics.
Scientists can test a substance to see whether it is acidic or basic by using an
indicator. Indicators are substances that will change colors when they come in contact
with an acid or a base

Why do we have to use indicators?
Indicators are a safe way to help scientists determine whether a substance is an acid or a base. Remember what we said about acids and bases. Often you do not want to come in direct contact with them as they can be harmful.
One example of an indicator is litmus paper, which will simply tell you whether a substance is an acid or a base. Litmus paper will not work since it can only tell you that they are both acids.
One way to determine how acidic or basic these substances are is to use solutions. This allows us to determine how acidic or basic a substance really is. another indicator. A universal indicator, such as red cabbage juice, will undergo a variety of color changes in different pH.

What are the different kinds of natural indicators we can use at home? And why do we use them?
The natural indicators are:
- Cranberry Juice - Grape Juice [use black grape]
- Elderberry Jam - Blueberry Jam
- Turmeric - Red cabbage
- Beets - Geranium petals
- Tea - Blueberries
- Petunia petals - Curry powder
- Carrots - Pansy petals
- Thyme - Cherries
- Poppy petals - Violet petals
- Onion - Purple peonies
- Strawberries - Rose petals
- Rhubarb - Tulip petals

Natural indicators:
We say “natural” because many of these indicators can be found in the food we eat, such as fruits and vegetables. They can also be found in flowers.
Red cabbage contains a pigment called flavin. This pigment is also found in red poppies, blue cornflowers, grapes, and apple skin. Depending on the pH of the fruit or plant the pigment will give a different color. This pigment can be used to indicate pH.
pH is the -log[H+]. Acids increase the concentration of hydrogen ions ([H+]) in a solution and therefore have a low pH. A base will increase the concentration of hydroxide ions ([OH-]) (decreasing the [H+]) in a solution and will have a high pH.
http://chemlearn.chem.indiana.edu/demos/REDCABBA.HTM

How do we make them?

Materials:
- red cabbage*
- blender
- hot or boiling water
- filter paper (coffee filters work well)
- 1 liter beaker
- Six 250 mL beakers
- household ammonia (NH3)
- baking soda (sodium bicarbonate, NaHCO3)
- washing soda (sodium carbonate, Na2CO3)
- lemon juice (citric acid, C6H8O7)
- vinegar (acetic acid, CH3COOH)
- cream of tartar (Potassium bitartrate, KHC4H4O6)
- Other household items that may be used include:
- antacids (calcium carbonate, calcium hydroxide, magnesium hydroxide...),
- seltzer water (carbonic acid, H2CO3),
- muriatic acid or masonry's cleaner (hydrochloric acid, HCl),
- or lye (potassium hydroxide, KOH or sodium hydroxide, NaOH).

Safety:
- Hydrochloric acid and Sodium Hydroxide are strong irritants.
- You should wear safety goggles and disposable gloves for this demo, especially if you choose to use HCl and NaOH.

Procedure:
- Chop cabbage into small pieces.
- Put cabbage in 5 liter beaker and then cover with boiling water,
let stand for 10 minutes or more (the more you wait the more potent your indicator).
OR**
- Put about 2 cups of cabbage in a blender, cover with boiling water, and blend.
- Filter out the plant material to get the red-purple-bluish colored liquid. This liquid is at about pH 7.
- Pour about 50 - 100 mLs of your red cabbage indicator into each 250 mL beaker.
- Add your various household solutions to your indicator until you see a color change.
- For example: Ammonia will turn your indicator green, NaOH -yellow, vinegar -red, and HCl - a deep red.
- You could do a neutralization experiment with the indicator. First add an acidic solution such as vinegar or lemon juice to get a reddish color, then add baking soda or antacids*** to bring the pH back towards a neutral 7.

Clean-Up:
All of the chemicals used in this demo can be washed down the drain with water.

Our results:

By: Arvin, Andrew, Vivian and Wenxin:)

CHEMISTRY ROCKS !!! 6:08 PM