Please note that this procedure was adapted from the “Observation of Chemical and Physical Changes” LabPaq Lab manual (Hands-On Labs Version 42-01-82-00-03, 2015)…
The pH indicator, phenolphthalein, turned a light shade of pink when it was in a solution with a pH of 7. Neutralization reactions occur when an acid is mixed with a base. The product of this reaction is a salt and water. These reactions are double displacement reactions, because the cation of the base mixes with the anion from the acid, forming a base, and the hydrogen from the acid mixes with the anion from the base, forming water. In this reaction, the sodium ion from the sodium hydroxide attracts to the acetate ion from the acetic acid, and the extra hydride ion bonds with the negative hydroxide ion to form water. The water produced by the reaction had a pH of seven, and so when the whole solution was light pink, we knew the reaction had fully…
solution and will stain skin and clothing. Avoid contact of all chemicals with skin and eyes.…
Procedure: Using a 96 well plate and a pipette each chemical was placed into its individual well, two drops of a second chemical were added and the observations of the reaction/changes were recorded. The new mixture was viewed on a light and on a dark background to observe all changes.…
In the Acid and Base Lab, we had to test the pH value of two unknown substances to determine if they were acids or bases. First, we had to test the Unknowns with litmus paper. Litmus is a dye made from a lichen-algae/fungus mixture. For the Unknown I, the litmus paper turned red which meant that it was an acid. For the Unknown II, the litmus paper turned blue which meant that it was a base. Next, we had to test the Unknowns with pH indicator paper. We then had to match the pH paper to the pH color chart. The pH value was 1 for the Unknown I. The pH value was 11 for the Unknown II. Then, we had to add phenolphthalein solution to the Unknowns. When we added it to the Unknown I, it turned cloudy and looked kind of milky. It didn't turn pink because it was an acid. When we added it to the Unknown II, it turned bright pink. This indicated that it was a base. Next, we had to add a piece of magnesium ribbon to the Unknowns. When we added it to the Unknown I, a hydrogen gas and salt was produced. It was an exothermic reaction because heat was given off. When we added it to the Unknown II, nothing happened. Then, we had to add baking soda to the Unknowns. Unknown I fizzed up to the top of the test tube and then went back down. Salt and water were produced. Unknown II turned light pink. There was no reaction because it was a base.…
Purpose: To observe some properties of chemical reactions and to associate chemical properties with household products.…
chemical were placed in a well along with two drops of another chemical. Chemical reactions and color…
H.|NaOH + phenolphthalein|A9|The NaOH was clear, but as soon as it was dropped into the well it turned a very light pink and after mixing it with phenolphthalein it turned into a strong sort of fuchsia pink. It looks about the same under black and white paper. |…
Objectives: 1. To examine a variety of reactions including precipitation, acid-base, gas forming, and oxidation-reduction reactions. 2. To identify the products formed in these reactions and summarize the chemical changes in terms of balanced chemical equations and net ionic equations. 3. To identify the species being oxidized and reduced in oxidation-reduction reactions and determine which species is the oxidizing agent and the reducing agent. Chemical equations represent what occurs in a chemical reaction. For example, the equation HCl (aq) + NaOH (aq) → NaCl (aq) + H2O (l) describes an acid-base reaction, a type of exchange reaction in which the driving force is the formation of water. In an exchange reaction, the…
1. How did your proposed procedures or flow charts at the beginning of this experiment compare to the actual procedures of this lab exercise?…
C. If the sample turned pink in color then I would make the assumption that the substance isn’t vinegar. I make this assumption because phenolphthalein turns pink when added to a base, not an acid. And since vinegar isn’t a base, the mixed substance should have remained clear instead of turning pink. Therefore, I do believe the substance is not vinegar.…
4. I will use goggles and cloves all the time, I also need to point dangerous materials away from other people and I should be specially cautious with hydrochloric acid.…
In a 50-mL beaker, 2-3 drops of phenolphthalein indicator was added to 9 mL of 0.1 M HCl. Then, 10 mL of 0.1 M NaOH was added drop wise with a pipet to the beaker of phenolphthalein and HCl. Observations about the color of the solution at each step was especially noted.…
The experiment is to observe a variety of chemical reactions and to identify patterns in the observation of reactants into products. The properties of the reactions will be analyzed to classify the chemical reactions into different groups.…
1. Write a balanced equation for each reaction observed in this lab. (10 points total, 2 points each)…
