Essay on Observations of Chemical Changes

1. Record your hypothesis about what will happen when Biuret solution is mixed with the solutions from test tubes 1, 2, 3, and 4 here. Be sure to use scientific reasoning to support your hypothesis.

Reaction 3- 1. Obtained a clean and dry test tube and placed a small amount ( about the size of a jelly bean) of ammonium carbonate into the test tube.

Suppose a household product label says it contains NaHCO3. How would you test this material for the presence of sodium bicarbonate?

The main objective of this experiment is to differentiate between a physical change and a chemical change.

After all materials were gathered, we then had to do five different tests to determine what the powder material does. The first test was to see what the powder materials do in water. We had to add a scoop of each of the common powders to an

The primary goal of this laboratory is to correctly identify an unknown substance. To achieve this task, one may use various tests that reveal both chemical and physical properties of a substance. By comparing the results of a known substance and the unknown substance, one may eliminate alternative possibilities and more accurately predict the undisclosed compound. Furthermore, by performing these tests, data can be collected and verified regarding chemical and physical properties of the unknown. Understanding the chemical properties of a known substance aids one’s understanding of the unknown based on comparative analysis of the results of the tests.

1. State a commercial use for biochemical testing as performed in this online laboratory. (5 points) face wash! To be able to test what different ingredients within the facial cleanser and how they will effect the areas, and chemicals of the skin composition.

In this experiment you will observe some physical and some chemical changes. You will observe that energy must be used to start some chemical reactions, and that it is produced in others.

The objective of this experiment will be to combine various substances, liquids and metals, and to observe their behavior when they are combined. The types of reactions observed shall determine the nature of these reactions: physical or chemical.

Purpose: The purpose of this experiment is to observe a variety of chemical reactions and to identify patterns in the conversion of reactants into products.

The purpose of this experiment is to distinguish the relationships between reactants and products, in addition to expanding on concepts such as single displacement reactions, mole ratio values, moles to mass, theoretical yields, limiting reactants, excess, stoichiometric relationships and percentage errors.

Well, as you probably already know, all beverages have different tastes and looks. But do all of them have the same or different reactions? Although beverages is an entity people drink on a daily basis. We don't know if it will have a reaction. This paper will examine, identifying beverages with its different reactions, the mass of a bottle and affect how the reactions are, and lastly, how it is manufactured. The goal of this paper is to prove that some beverages will have or will not have a reaction.

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 purpose of Experiment 3 was to determine the pKa of a common acid-base indicator and color dye, bromothymol blue. Acid-base indicators are usually weak acid or base that change color with various pH levels in a solution, giving one specific color for acidic solutions (HIn) and another color for basic solutions (In^-). In the case of bromothymol blue, a weak acid, the reagent turns yellow in the presence of an acidic solution and turns blue in the presence of a basic solution. As the pH of the solution containing bromothymol blue changes, the equilibrium can either shift towards the reactants (Hln) or the products (In^-). Since bromothymol blue is a weak acid, it’s equilibrium equation can be written as: Hln=H^++In^-. The solution color will change depending whether there is more reactant or product present and additionally, whether it is more acidic or basic. Based

In our daily life, we constantly have interactions of chemical reactions, such as endothermic and exothermic reactions. In general all chemical reactions are important to our society to achieve certain activities. Some examples are smelting iron,making class, burning fuels,brewing beer, making wine and cheese, and etc. Most importantly I will be researching what are exothermic and endothermic reactions and how they can affect our daily life.