Lab+3+Water

__ **Exercise 1: Colorimetric Detection of pH ** __ **1. ****What IS pH? ** -The pH is the measure of the basicity or acidity of an aqueous solution. The pH amount is determined on a number scale from 0-14. Anything with a pH of 7 is said to be neutral, such as water. A substance that is less than 7 is said to be acidic. Vinegar and lemon juice are examples of acidic substances. A substance that is greater than 7 on the pH scale is said to be basic. Bleach and baking soda are examples of basic substances. **2. ****What makes hydrogen chemically active? ** -Hydrogen is chemically active due to the fact that it has one electron and is able to bond with other elements. **3. ****What does it mean when something is acid? ** -An acidic solution is a substance that is less than 7 on the pH scale. Acidic substances have higher hydrogen ion activity than hydroxide ion activity. **4. ****What does it mean when something is basic? ** -A basic solution is a substance that is greater than 7 on the pH scale. Basic solutions have a higher concentration of hydroxide ions than hydrogen ions. **5. ****How much more acidic is something that is pH 3 than pH 4? ** -Since the pH scale is based on the logarithm base 10 each point is 10 times more acidic as it increases from 3 to 4. So pH 4 is 10 times more acidic than pH 3. **<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">6. ****<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">How does the acidity or alkalinity of food affect human taste buds? ** <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%; margin: 0in 0in 10pt;">-Acidic food substances leave a sour taste on the human taste buds while alkaline food substances leave a salty taste on the human taste buds. **<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Summary: ** <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%; margin: 0in 0in 10pt;">-Acid-base balance has to do with the level of acidic and basic substances in the body. The amount of acid in the body increases when someone either consumes more acidic substance or decreases the amount of basic substances. The amount of alkaline in the body works in the reverse order. The acid-base balance takes place in the blood of a human. It is very important to maintain the balance because it can lead to serious damage to many organs if the balance got out of hand. The kidneys, buffer systems, and lungs each play certain roles in helping to maintain this balance. Of all the buffer systems, the carbonic acid-bicarbonate buffer is the most important. Its job is to maintain the pH in the body. The carbonic acid works clearly as the acid while the bicarbonate works as the base. These two are in equilibrium in the blood stream. When carbon dioxide is dissolved in water, carbonic acid is created. When this acid gives off a hydrogen ion that is when the bicarbonate ion is created.

__**<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%; margin: 0in 0in 10pt;">Results of Using Red Cabbage as a Colorimetric Indicator **__
 * **Chemical added** || **Number of Drops** || **Color** || **pH using paper** ||
 * **Control** || 0 ||  ||   ||
 * **Vinegar** || 13 drops || light pink/purple || 3 ||
 * **Baking Soda** || 1 pinch, 17 drops || blue and more cloudy || 8 ||


 * __Effect of Buffer on pH Change in Reaction to Vinegar Addition__**
 * **Tubes** || **Number of drops(each attempt)** || **color** || **pH using paper** ||
 * Control || 85, 93, 89 || light pink || 4 ||
 * Buffer || 16, 19, 17 || light blue || 9 ||