1. What type of macroscopic evidence for chemical change did you observe during this experiment? Give at least three different examples. (15 points) The main evidence of chemical change in this lab is the change in color, production of gas, and the production of precipitate. These reactions can be seen from just a little bit of reaction all the way up to a complete change of the entire sample tested. Some samples of those tested in this experiment which showed the chemical reaction were the baking soda/ammonia mixture, the Epson salt and baking soda mixture as well as the food coloring mixed with the baking soda and bleach. 2. Which reactions, if any, do you believe showed no evidence of chemical change? Justify your reasoning. (15 points) There was one combination that did not have any reaction when tested. This combination was the MgSO4 and CH3COOH. The reason that the reaction did not happen is because they created a mixture and not a chemical change. 3. …show more content…
When two solutions combine and a solid substance is formed, this solid is called a precipitate. In your experiments, if the clear reactant solutions you combined together formed a cloudy product, then a precipitate (solid substance) was formed. Describe the precipitates (according to color and clarity) and the substances that formed them. (18 points) The combinations that formed precipitates in my experiment were MgSO4 and NH3, MgSO4 and Na2CO3, Na2CO3 and CH3COOH. The two most obvious formation of the precipitate were the combinations with the MgSO4. The MgSO4 and NH3 solution became very opaque and the MgSO4 and Na2CO3 turned from liquid to a full solid white substance. The Na2CO3 and CH3COOH did not have as strong of a reaction, however, the precipitates were able to be visualized with in the clear
Equipment- 250mL beaker, 125mL Erlenmeyer flask, cardboard square, chemical scoop, metric ruler, lab countertop, rubber stoppers, safety goggles, lab apron
Procedure: In this experiment, various chemicals were mixed together, to determine a reaction. Using two drops from chemical 1 and two drops of chemical two, unless otherwise stated, then recording the type of physical reaction or color changes that occurred.
The purpose of this particular lab was to experiment and identify the chemical and physical changes throughout the experiment.
The main objective of this experiment is to differentiate between a physical change and a chemical change.
The Vitamin C turned to a red/orange color with no physical/chemical reaction. For the salt the solution turned to an orange color with no physical/chemical reaction. With the Alka-Seltzer, the solution turned to a brown color with no reaction as well. Last but not least, the Baking soda turned to an orange/brown color with no reaction.
Solub. Or Reaction w/ hot H20: no change observed from the cool water and is soluble
There was an assortment of different changes indicating that chemical changes were taking place such as change in color or chemicals bubbling when combined with another chemical.
The objective of the experiment was to observe different reactions with different chemicals. The experiments emphasized on the chemical changes occurring in acids and bases as well as color changes and bubble formations. The experiments allowed for a better understanding of the undergoing chemical changes in mixtures. Some mixtures instantly changed colors while others were transparent or foggy. Some mixtures produced thick color that created solids called precipitates. Mixtures KI + Pb(NO3)2 and NaOH + AgNO3 both produce noticeable precipitates after a while. It was interesting to see the different acidic and base reactions like the fuchsia color formation in NaOH + phenolphthalein.
The second purpose of the maalox lab was to use visual evidence and energy changes to see chemical changes. One way that we could see the chemical changes was by observing how the appearance and solubility of the products changed versus the reactants. During the first reaction, one of the reactants, which was ammonia, was a transparent liquid that had a low viscosity and was water-soluble. The other reactant, alum, was a white powder with a grainy texture. When both reactants combined with each other, they formed the product called aluminum
Many signs show that a chemical reaction has occurred. Some ways we know there is a chemical reaction are the formation of gas, formation of precipitate, change in temperature, and,or change in color. In part one of the experiment, we know there was a chemical change because of the formation of the white precipitate. We poured the ammonia and water in the flask with alum and water, forming a white, cloudy substance in between the two liquids. The white, cloudy substance between the two is liquids is also known as aluminum hydroxide. The second part of the experiment was very similar to the first, but in the second part we mixed epon salt, water, and ammonia. The precipitate formed from mixing the epson salt, water, and ammonia was called magnesium hydroxide.
There are five clues that help indicate if a chemical change occurs. The clues to a chemical change include a change of colour, the forming of a precipitate, the forming of gas bubbles, the production of heat or light, and if the change is difficult to reverse. In the chemical reactions lab, several chemical changes will occur. Participants must use this knowledge to decipher what change has occurred after the chemical
At station A when zinc and hydrochloric acid react with each other it is a chemical change because it creates gas bubbles and temperature change. At station B where NaOH solution and phenolphthalein react with each other it is a chemical change because it changed to the colour purple and the change looked difficult to reverse. Station C in which sulfuric acid and magnesium were to react with each other is a chemical change because it formed gas bubbles and changed colour. Station D where hydrochloric acid and Bromothymol blue were the materials is a chemical change because it changed to the colour yellow and looked difficult to reverse. In Station E where NaCl solution and AgNO3 solution were the materials is a chemical change because the reaction
Type of Reactions We did a lab on many reactions to find the products of the reactions. We conducted four group experiments and three class experiments, following very strict safety procedures given to us by our instructor. We used goggles and aprons which were required at all times. We could not sniff any gasses or walk into clouds of smoke unless we were instructed to.
, it is a reaction became the color of the solution turned yellow. Discussions. The first experiment was clearly a synthesis, as the Magnesium and the flame reacted and combined, forming 2MgO. The reason of the 2 Mg is because all chemical equation must be balanced, and the total electron number must be zero. A O have a -2 charge, while Mg have a +1 charge.
This paper is about chemical reactions and chemical reaction types. All the data gathered was from conducting multiple experiments. Each experiment was performed carefully and analyzed to obtain the necessary information for the paper. That information included the four signs of a chemical change, the rnx type, and more.