The purpose of this lab was to find out the indications of chemical changes and reactions when mixing two different substances, which are listed specifically in the Observations section. The purpose is also to find out how a percent by mass solution is made up. The data and observations that is recorded will help find out the indications of chemical changes and reactions. Since this is a very big part of the lab, it is imperative to take detailed notes and observations. Besides recording data, it is necessary to know how to calculate it. It will be needed to find out how a percent by mass solution is made up. It is also very important to have a good method of approach towards calculating this data because this is what drives the whole lab. Without the percent by mass solution calculations, we would not be able to make up the chemical solutions.
[...] In result, you are going to have unwanted chemical reactions, which can throw your observations off. Human error could not have been a big part in our lab. It was carried out with the most care. Other Observations This lab was carried out fairly well. The safety rules were followed very carefully and no one got hurt nor did many accidents occur. All the isles were cleared very well and all the materials were put away when it was time to go. [...]
[...] Chemical changes can also be indicated by precipitates. A big percentage of the solutions had precipitates: 1b, 2a, 2b, 2d, 3a, 3b, 3d, 4b, and 4c. Small particles were formed almost like crystals and they sank to the bottom of the test tube. After measuring the pH of the solution with the master chemical already in it, in most cases it appeared to be what the master chemical was. For instance, after pouring sulfuric acid into 2a, it became an acid; the same pH as the [...]
[...] There are numerous ways that make it evident that a chemical reaction has taken place. After a necessary amount of a master chemical has been poured in a container, different occurrences that take place within the container will define different chemical change. First of all, after pouring the master chemical it will be necessary to see one of the following occur: a texture or color change, the solution becomes effervescent, thermal change, and/or precipitates. A color change may occur right away, or it may occur within a couple minutes after pouring the master chemical into the solution concentration. [...]
[...] Precipitate Went from light light and formed. ACID to darker cloudy cloudy. BASE. blue. BASE. precipitate white little bubbles clouded into a developed. It precipitate. and then it got white jell-like was at first ACID. cloudy. affect. It was a clear and then BASE. solid. BASE. turned cloudy and foamy. The white precipitate sank to the bottom. ACID. turned pink and formed some bubbles and orange then then purple at (effervescent). it turned light changed to a the top. After Clear. [...]
[...] (This can be done various ways, the easiest is to just distribute 3mL of tap water to each of them and mark them with the wax pen) Pour the tap water out of the test tubes and wash them out a little bit with DI water Pour 3mL of the master chemical into each of the 4 test tubes React each one of the assigned solutions with the master chemicals. To do this, you must pour 3mL of each assigned solution into different test tubes already filled with 3mL of the master chemical Record observations on the chemical change. [...]
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