8th Grade Chemistry Essay

We were assigned mystery powder convertible which contained calcium carbonate, baking soda, and sucrose. We found out that the mystery powder had calcium carbonate because when it reacted with iodine it turned orange/brown. When calcium carbonate reacted with vinegar it had a fizzy-like reaction. It also reacted with hydrochloric acid and that caused it to bubble. When we tested the mystery powder it also turned orange/brown when we added iodine. Also when we added vinegar and it also fizzed like the calcium carbonate. Again when we added the hydrochloric acid it reacted exactly like calcium carbonate, lots of bubbles were made. We know that the calcium carbonate was in the mystery powder because it had similar reactions.

B. Claim: As we go from methanol  ethanol  1-propanol  1-butanol the dispersion forces increase.

A chemical change is a change that alters the identity of a substance. A chemical change can be identified by five things: change in mass, formation of a precipitate, release of heat and/or light, color change, or giving off gas.

The goal of the experiment was to identify Unknown 33A and 33B. Unknown 33A was a white, crystalline solid that had a sweet cherry smell and Unknown 33B was a beige, yellowish color liquid that was translucent and had a viscosity similar to water. Also, the liquid was homogenous and smelled sour, similar to mildew.

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.

What is the appearance of reactant, Evidence of chemical reaction, and properties of a product?

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.

In the last test, we had to test out a mystery powder (powder A, B, C), in its own separate test tube, in order to solve the Sherlock Holmes Mystery. Our group had powder C. When we mixed water in the mystery powder, it did not dissolve. When the litmus paper was put into the test tube it turned blue. When the vinegar was mixed it bubbled/foamed up. When we mixed the iodine solution, there was no reaction and the solution turned to a dark brown/black color. When we mixed in the baking soda there was no reaction and it turned to an even darker color.

Science and Chemistry Assignment 2 (Chapters 4 and 5) 1. Carbon is considered a unique atom because it can bond to four other atoms or groups of atoms which makes a large variety of molecules possible. 2. The Carboxyl group acts as an acid and the amino group acts as a base. 3.

Abstract: Cold packs are based on the principle of endothermic reactions, which means a reaction that absorbs heat from the surrounding resulting in a temperature drop. Due to this temperature drop, cold packs have many benefits when it comes to injuries such as sprains and strains. It cools the local tissue and reduces bleeding, swelling and pain. It also aids in a speedy recovery. The most commonly used chemical in instant cold packs is ammonium nitrate which will be tested in the investigation along with four other chemicals in water. These other chemicals include potassium nitrate, potassium chloride, sodium acetate and sodium chloride. The

Mrs. Collins addressed the 6th grade Science class with the most uplifting positive attitude that anyone could have. Every day she came to class she always had candy and snacks sitting on her desk for students to enjoy when they were on their best behavior or if students participated. Everyone insisted on behaving and participating just so they could get a treat. One day Mrs. Collins called on a young boy whose name is Mark, but everyone else addressed him by meanie mark. Mrs. Collins asked Mark if he would like to come to the front of the class and demonstrate the Mentos and coca cola project. Mark did not say anything the first time. The second time she asked he murmured something, no one could not hear what he said. He set in the far back left corner of the classroom by himself. No one wanted to sit next to Mark for he intimidated everyone that he came across. He always wore black and he never spoke to anyone no matter how nice they were and he always had his head down. Mark was a loner. Furthermore

The purpose of this lab is to test substances and to determine the physical and chemical properties of substances.

When identifying the unknown compound, the top three predictions were: acenaphthene, phenoxyacetic acid, and benzil. Based on the melting points (see Table II.), the unknown solid compound was most likely to be acenaphthene. Before the melting process, the unknown was observed to be white, flaky, shiny, and soft. When it was mixed with other compounds, the characteristics began to change. For instance, when the unknown was mixed with acenaphthene, the solid was grainy and white.

Physical changes can be seen through an altering of the substances physical property. A substances physical property is observed and measured without changing the composition of the subject. Descriptive words that would help to identify a substance’s physical property include hard, soft, brittle, flexible, heavy, and light just to name a few.

This is a simple equation that doesn’t properly prove the reaction. It is very complex and starts with this: