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Procedures and practices in a lab
Procedures and practices in a lab
Chemistry lab practical
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Recommended: Procedures and practices in a lab
Shusanta Bhattarai
Ms. Kelley
Formal lab report
The conservation of Mass and how it’s connected to chemical reactions
Introduction
In this lab, we were looking at the conservation of matter, chemical reactions and using mass to find the number of moles present after a reaction. We had previously studied moles (measurement system) and mass. We copiously took notes on the masses of the objects after reactions and observed how the quantity would “change” after a chemical reaction. The conservation of mass is a law that states a mass will stay consistent over time and will not change until it is not combined or removed. We performed a lot of chemical reactions in this lab. The first part of the lab was putting a coiled piece of copper in silver nitrate and washing it out with water. The second and third part was also about adding chemicals and seeing the reactions. The purpose of the experiment was to determine if the values of silver and silver nitrate would stay the same. The hypothesis was that if chemical elements and compounds react the ratio would stay the same, due to the conservation of mass and the law it has.
Procedure
Originally, I was supplied with 30 cm of copper wire and a test tube. First, the wire was cleaned with steel wool.The copper wire was coiled around the full length of the test tube. The copper was then weighed. Then an empty 250 ml beaker that was labeled by my partner was weighed. A vial of white silver nitrate was also weighed. After, 2/5th of the clean beaker was filled with distilled water and the solid silver nitrate was stirred in with the water until the crystals that were formed dissolved. Then the end of the copper wire was bent so we could submerge the coil in the solution and still be able t...
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...s is attached and the mass must remain consistent over time. The chemical process did not change the quantity and it showed.
4. The ratios might be different because there might have been a flaw in the procedure. They all still surround 1 and no one in the class got one but we all got something close.
5. I think that the decanting process was the main source of contamination. Sometimes water doesn’t take out all the specks. We could buy a high tech decanting type-system and walk through each student individually so that there would be minimal chance of error.
Conclusion
We saw that no matter the chemical change we would get the same ratio. The purpose worked out in a great fashion and showed us that the quantity was almost the same. The whole class got a number that was close to one. The hypothesis was supported because the conservation of matter proved to be true.
The experiment done in the lab supports the law of Conservation of Mass because we used the reactants and simply rearranged them to create the products without adding or removing anything. For the experiment we used candy and marshmallows. The green candy symbolized carbon atoms, the red ones hydrogen atoms, and the marshmallows represented oxygen atoms; we also used toothpicks which illustrated bonds keeping them all together. The chemical reaction for photosynthesis is the product of six carbon dioxide plus six water atoms is glucose (sugar) plus oxygen. We started by making the food into the reactants, the ingredients for the chemical reaction; six green candy drops and twelve marshmallows plus twelve red candy drops and six marshmallows.
Mass Pb(NO2)3/ MW Pb(NO3)2 to find the mass of SO4, which equaled 0.1394g, then plugged into the percentage was exactly 55.75% SO4. The begging of the experiment requested that the percentage of SO4 in their fertilizer sample be found and that is exactly what was accomplished by this experiment, and the outcome, demonstrating the ability of my group to preform the requested task presented by the
The Gravimetric Stoichiometry lab was a two-week lab in which we tested one of the fundamental laws of chemistry; the Law of Conservation of Mass. The law states that in chemical reactions, when you start with a set amount of reactant, the product should theoretically have the same mass. This can be hard sometimes because in certain reactions, gases are released and it’s hard to measure the mass of a gas. Some common gases released in chemical reactions include hydrogen, carbon dioxide, oxygen and water vapor.
The experiment started by labeling a piece of filter paper with my initials with the following A, B, C, oil, and H2O. I placed two drops of each unknown milk sample, vegetable oil, and H2O next to the labels on my filter paper and allow to air-dry. After these samples were dried, I placed the filter paper in a petri dish containing Sudan IV solution and stained the filter paper for one minute. I then used the forceps to remove the filter paper to the rinsing dish. Then, I rinsed the filter paper with water and collect the runoff in the dish. The last step, I placed the filter paper on the table and allowed it to
The procedure of the lab on day one was to get a ring stand and clamp, then put the substance in the test tube. Then put the test tube in the clamp and then get a Bunsen burner. After that put the Bunsen burner underneath the test tube to heat it. The procedure of the lab for day two was almost exactly the same, except the substances that were used were different. The
== = == Hypothesis for the experiment: After I conduct this experiment, I expect and suppose I can recognize and physical changes, identifying the difference these two kinds of changes. Also, I will be able to know some physical and chemical properties of copper (II) sulfate, water, iron, sodium carbonate, hydrochloric acid and magnesium and identify if it is a chemical change or physical change in each part of the experiment.
Planning Firstly here is a list of equipment I used. Boiling tubes Weighing scales Knife Paper towels 100% solution 0% solution (distilled water) measuring beakers potato chips Cork borer. We planned to start our experiment by doing some preliminary work. We planned to set up our experiment in the following way.
are said to be in the same ratio, the first to the second and the third to the
A good example would be the experiments with the concentrations of 20% to 60% concentration results to show the change. In the 20% concentration I noticed a decrease in the percentage change in mass for the experiment the percentage was _____ while for the concentration of sucrose 60% the change was _____ we can see that the percentage change in mass is decreasing thus we can conclude that the difference of the initial from the final and as it gets greater that means the mass of the potato changed massively.
Quickly and carefully transfer the heated metal from the test tube to the water in the calorimeter.
== § Test tubes X 11 § 0.10 molar dm -3 Copper (II) Sulphate solution § distilled water § egg albumen from 3 eggs. § Syringe X 12 § colorimeter § tripod § 100ml beaker § Bunsen burner § test tube holder § safety glasses § gloves § test tube pen § test tube method = == = =
Part A of the experiment, we were measuring the density of water. In this part, we measured by difference by measuring the mass of the empty graduated cylinder which was 46.35 grams and then added 25.0 milliliters of water to it. When subtracting by difference, our mass of the water was 25.85 grams. This was close to the measurements of the water added to the graduated cylinder. The density of the water was 1.0 grams/milliliters.
...e could add the mass piece without having them fall off. At the time of the experiment, this was not seen as a threat to our results.
Safety in school labs Safety remains one of the key elements in modern school labs; it is necessary for the staff to ensure the safety of all the lab users. All chemicals and equipment in the laboratory have the potential to harm if adequate safety measures are not taken into account. For lab use, you have to ensure that you follow the basic safety guidelines for the lab sessions. Always be aware of all the general safety precautions and familiarize yourself with the appropriate protective measures that can keep you safe (NIOSH, 2006). It is important to consider that serious damage could occur if the basic safety rules and regulations for lab practice are not followed.
There is also the potential of human error within this experiment for example finding the meniscus is important to get an accurate amount using the graduated pipettes and burettes. There is a possibility that at one point in the experiment a chemical was measured inaccurately affecting the results. To resolve this, the experiment should have been repeated three times.