Investigating the Relative Atomic Mass of Lithium
Background information
I’m going to produce a piece of coursework, which determine the relative atomic mass of lithium.
Two methods are going to be used to approximate the relative atomic mass of lithium.
1) In the first method the RAM (Relative atomic mass) of lithium is determined by the Volume of hydrogen gas produced.
2) In the second method the RAM of lithium is determined by titrating the lithium hydroxide produced.
To some extend, I think that the first method is the most practical and less complicated, because the less calculations has to be done. Hence it is more easer to measure the volume of hydrogen gas.
Test-1
My mission was to find
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This is not what I was expecting, because in the real sense of things the second method should be more accurate. This is due to the more precise equipment that was used in the second method, e.g. pipette, burette. This unexpected outcome could be explained in terms of experimental error. ======================================================================
I noticed that in the first method the experimental error was lower than that of the second method; this suggests that second method is more inaccurate than first one in my experiment. Therefore we had an unexpected outcome. ====================================================================
Evaluation:
One of the best methods for determining mass in chemistry is gravimetric analysis (Lab Handout). It is essentially using the the mass of the product to figure out the original mass that we are looking for. Thus the purpose of our experiment was to compare the final mass in our reaction to the initial mass and determine the change in mass.
The only materials needed in the experiment were a single dial caliper, and the skin of the participant that was measured (Lab Manual). A dial caliper was available for purchase online through the use of a simple Google search. The dial caliper was a long metal object with one dial, that was adjustable and that moved the two sharp points at the end of the caliper further away from each other. The purpose of the dial caliper was to measure the length of space between the two sharper points of the dial caliper.
Switch to a solution of 1 part water to 1 part ammonia or 1 part water to 1 part hydrogen peroxide....
The oxalic acid dehydrate solution was titrated using NaOH solution until light pink color can be seen. (does not disappear when the solution was mixed).
· I made sure I put the same amount of water in the copper can.
...for the original titration, shown in Table 5. This could be due to perhaps usage of the wrong indicator, or of not stopping the titration exactly when the color changed.
3. Now take the time it takes for the dye to get a clear color. (To
Once a value for e/m was obtained the mass of an electron can be calculated using this ratio and the charge of an electing (e=1.6 x 〖10〗^(-19) C). The result from this experiment was of an order of 〖10〗^6 times too large. Subsequent errors would of have lead to this but in principle the mass of an electron can be measured if the charge of an electron is known.
Another problem with this experiment was determining at which stage the solution turned completely clear. I had a black piece of card, which I held behind the boiling tube to see when the solution turned clear, however this was not very efficient. I think that it would have been better if I had gotten a white piece of card and wrote a black letter on it, then looked through the solution until I could clearly see the letter.
This experiment's purpose is to calculate small values (molecular and atomic size) in different phases, such as a gas, liquid, and solid by using practical methods. If the molar mass is known, one can estimate the atomic size through practical measuring techniques with little experimental error. This experiment consists of measuring a block of a solid element (Copper and Zinc), measuring the volume of the lead pellets, and measuring the amount of carbon dioxide gas in a balloon. These experiments will allow one to estimate the atomic or molecular size by using doable measurements and calculations.
After the solution was stirred, the solution turned into a mustard yellow color. When the luminol was dissolved into NaOH the solution turns a dark brown color. After the water was added into stock solution A, the color appeared medium brown. Following this, after the potassium ferrycyanide and hydrogen peroxide were mixed, stock solution B was made and appeared a yellow color. When stock solution B was diluted with water the resulting solution B appeared a to be a light yellow. Finally, after diluted solution A was added to solution B in a dark room the appearance of the solution was a glowing blue
You really enjoyed using the blue dye, you sprayed a good portion of the paper with your blue dye. Once you had finished using your blue dye you swapped colours with Madison who had the green dye. Moira,
In the second experiment with the green color, I can safely conclude that the color green in this case is very soluble and we would need longer filter paper, perhaps more time to safely separate the different colors that make up the color green.
Determining the Relative Atomic Mass of Lithium An experiment has been carried out to determine the relative atomic mass of Lithium by using two different types of methods The first method that was carried out was to determine the volume of Hydrogen produced. In this experiment a fixed amount of Lithium was used, in my case it was 0.11g. At the end of this experiment, the volume of Hydrogen gas I collected was 185cm³. Then using the solution of lithium hydroxide made from experiment one, I used it in the titrating experiment, to find out the total volume of Hydrochloric acid used to titrate the lithium hydroxide. RESULTS TABLE Experiment Initial Volume ( cm³) Final Volume ( cm³) Total volume Of HCl used ( cm³) Rough 0.2 30.3 30.1 1 6.3 35.8 29.5 2 2.7 32.0 29.3 Average 29.6 CONCLUSION Method 1 [IMAGE]2Li (s) + 2H20(l) LiOH(aq) + H2(g) Number of moles of Hydrogen. Volume of hydrogen gas was 185 cm³. Weight of Lithium was 0.11g. N = __V__ _185_ = 0.0077 MOLES 24000 24000 Number of moles of Lithium.
her marker. It seems she had put it in a wrong box. This turned out