Acids Bases Ph Lab

Purpose: The purpose of this experiment is to observe chemical changes in common consumer products to determine if the chemicals are basic, acidic, or remain neutral when mixed with other chemicals.

Purpose/Hypothesis: The purpose of this experiment is to use both cabbage juice and pH paper to determine the pH of household items. This way, we can tell which products are basic and which one are acidic. If we use cabbage juice as an universal pH indicator by comparing it to pH paper then pH determined by the cabbage juice will be unstable because by using cabbage juice, it can be different depending on how diluted it is.

Does the amount of active ingredient in different types of tablets decrease or increase per milligram after its expiration date? Overtime, the concentration of acid in a low dose aspirin tablet increases, as the concentration of acid in a high dose aspirin tablet decreases. However, due to various experimental errors, the claim is not a strong and compelling one. What is assumed to have happened is that both low dose aspirin tablets and high dose aspirin tablets increase in concentration of acid as the expiration is surpassed.

1. What was the purpose of using water as a sample in some of the tests performed in the lab? (2 points) to have a control.

In 2 and 7 I added 50 mL of .1 M NaCl. I added sodium acetate to the rest of the beakers: 1 gram to 3 and 8, 5 grams to 4 and 9, and 10 grams to 5 and 10. I then filled the beakers that contained the solid sodium acetate with 50 ml of .10 M acetic acid. Specifics can be found on page 84 of the lab manual. Though the lab manual instructed to use a pipet, we did not have an accurate 1 mL pipet or a graduated pipet, so we instead prepared two graduated burets with 1 M Sodium Hydroxide and 1 M hydrochloric acid. Using a standardized pH probe with a Lab Pro to measure changes in pH, we added 1 mL of HCl at a time and recorded the changes. The same was done for the NaOH.

To start out this study the difference between acids and bases has to be identified. Acids have very low pHs and have a high concentration of hydronium ions, while bases have a high pH and have a high concentration of hydroxide ions. The difference between strong bases and acids, and weak bases and acids is the amount of dissociation. Strong bases and acids dissociate a large amount and let go of their ions in solution, while weak bases and acids may only let go of some of their ions. This is important because if the unknown solutions aren’t strong acids or bases then using their ions to calculate the pH of the solutions will give false results (Diffen 2012).

Three grams of a mixture containing Benzoic Acid and Naphthalene was obtained and placed in 100 ml beaker and added 30 ml of ethyl acetate for dissolving the mixture. A small amount (1-2 drops) of this mixture was separated into a test tube. This test tube was covered and labelled as “M” (mixture). This was set to the side and used the following week for the second part of lab. The content in the beaker was then transferred into separatory funnel. 10 ml of 1 M NaOH added to the content and placed the stopper in the funnel. In the hood separatory funnel was gently shaken for approximately one minute and vent the air out for five seconds. We repeated the same process in the same manner one more time by adding 10ml of 1M NaOH.

Problem & error: Write a paragraph about the issues you had in performing this lab. What went well, what did not go so well? What could you have done to improve your performance on the lab?

By using the pH paper to measure the solutions A through E it would point out what substance is an acid and which one was basic. Also, by adding Bromothymol blue and Phenolphthalein afterwards to the solution it would indicate what color it would turn to when mixed into an acid and a base.

Vinegar, Lemon Juice, and Soda are the acidic household solutions. I can tell this because they turned pink when cabbage juice was added. Also, their pH’s are less than 7.

By using acid-base titration, we determined the suitability of phenolphthalein and methyl red as acid base indicators. We found that the equivalence point of the titration of hydrochloric acid with sodium hydroxide was not within the ph range of phenolphthalein's color range. The titration of acetic acid with sodium hydroxide resulted in an equivalence point out of the range of methyl red. And the titration of ammonia with hydrochloric acid had an equivalence point that was also out of the range of phenolphthalein.. The methyl red indicator and the phenolphthalein indicator were unsuitable because their pH ranges for their color changes did not cover the equivalence points of the trials in which they were used. However, the

The pH of a solution is the measure of the concentration of charged Hydrogen ions in that given solution. A solution with a pH lower than seven is considered to be acidic. A solution with a higher pH is a base. It is very important for organisms to maintain a stable pH. Biological molecules such as proteins function only at a certain pH level and any changes in pH can result in them not functioning properly. To maintain these constant pH levels, buffer solutions are used. A buffer solution can resist change to small additions of acids or base’s. A good buffer will have components that act like a base, and components that act like an acid.

Maintenance of acid and based balance in the body is essential for normal function of biological processes, mainly because of the dependence of pH level for enzyme function. The body concentration of acids and bases is controlled so that the pH of extracellular body fluids is maintained within the range of 7.35 to 7.45. The body maintain this balance by a mechanism that generate buffer and eliminate acids and bases. A base is an ion or molecule that can accept or combine with a hydrogen ion and an acid is a molecule that can release a hydrogen. (Grossman, Port, 2014).

This experiment will investigate if small changes in my diet will alter the pH of my saliva compared to the 10 other subjects I will test it on. The objective of this experiment tests how the little changes in my diet and others affects the pH of saliva. Well, since my question is how my diet affects pH, I already know a few things. There are two possible types of food that affect the pH of a body, alkalizing and acidic foods. Alkalizing foods include: apples, mineral waters, grapes, and many more. Acidic foods include: corn, blueberries, rice, and many more. Certain acidifying diets are claimed to lower the pH of your body, while alkalizing diets may raise your pH. Also, I know that the average pH of a body should be at or around a range from 7.35 – 7.45. The main regulators of a body’s pH are the respiratory system and the renal system. If an individual’s blood pH drops, then the body breathes faster, the opposite occurs for when an individual’s blood pH rises, the body breathes slower. Factors such as stress, diet (obviously), and emotions are all prone to affecting the pH of one’s body. In additions, Say your body has a low pH, it will try to compensate by using all the alkaline minerals in the body. In this experiment, for sanitary purposes, I will be testing the pH of 10 people’s saliva, instead of blood.

I predict that out of the 20 solutions that we are going to be testing, about 6 of them will be an acid, 3 will be neutral and 11 will be a base.