The unknown samples are strontium chloride and copper chloride. Some of the errors that might’ve occurred during our experiment could’ve been due to the fact that we didn’t have much time. Therefore, we rushed through the experiment and might’ve not washed the spatula properly before dipping it into a new substance. Due to this, the color of the flames emitted could vary and not be accurate because the different substances could’ve mixed. Lack of equipment could’ve been one of factors that contributed to our errors.
This would affect the volume of gas captured in the pipette. And with a limited amount of sucrose its possible sucrose wouldnt properly fill in as a source of glucose for cellular respiration. Another source of error would be that we didnt let the burner heat up all the way to the correct temperature so that would affect the outcome massively and significantly. Also when we had 10% sucrose, we only recorded the time two times, compared to the other percentages of sucrose where we had many other trials and times recorded. We also found problems when we had placed clay on the tip of the pipette to seal the air out.
Obtain another 50-mL beaker and add 0.05g of Chromium(III) Nitrate to the beaker. Then, add 17 mL of distilled water and mix until the solid is dissolved. 3. Obtain a final 50-mL beaker and add 0.05 grams of the unknown substance to the beaker. Add 17 mL of distilled water and mix with a stir bar until the solid is completely dissolved.
h) A way to make hard water softer is to put an sodium nitrate and create a precipitate to mellow out the reaction. Another way of making it softer is by removing the calcium ions one way of doing that is by boiling the solution to take out some of the ions. Conclusion: Overall, we determined that sodium carbonate, Na2CO3, is the anion that can be used to precipitate the most metal cations. Also, we learned that the anion sodium chloride, NaCl, could be used to remove silver ions from solutions. The stuff that I found interesting was that how many colours you can get when you mix the cations and anions
Once a light blue solution remained, 5mL of distilled water was added. This solution was then placed onto the magnetic stir plate and magnetic stir bar was placed in liquid solution. Then to the solution .75g of zinc was added to solution. Then once the solution was colorless, the solution was removed from magnetic stir plate and the liquid was decanted away from the copper. Then 5mL of HCl was added to copper to completely remove all traces of zinc.
The following data were obtained when a sample of barium chloride hydrate was analyzed as described in the Procedure section. Calculate (a) the mass of the hydrate, (b) the mass of water lost during heating, and (c) the percent water in the hydrate. Mass of empty test tube 18.42 g Mass of test tube and hydrate (before heating) 20.75 g Mass of test tube and anhydrous salt (after heating) 20.41 g. Mass of the Hydrate is 2.33g. Loss (H2O) is 0.34g. Percent H2O in Hydrate is equal 0.34/2.33=14.6% 3.
An error that could have occurred is that the students did not leave the crucible on the hot plate long enough for the color to change. Another error could have been that the temperature was not hot enough. In order to correct these errors, the students would need enough time to do the experiment thoroughly and would also need to check the temperature on the hot plate. References: Deng, Yuanjian, and Sapp, John B. General Chemistry Laboratory Fifth Edition.
White precipitate shows the presence of chloride (Cl-). Chloride anion equation: HCl(aq) + AgNO3 (aq) → HNO3 (aq) + AgCl(s). The nitrate anion test involves cooling a mixture containing 1 mL of test solution and 3mL 18M H2SO4. 2mL is poured down the inner test tube side and the presence of a brown ring shows nitrate (NO3-) to be present. The carbonate anion test mixes 1 mL of test solution and drops of 6M HCl.
Initially it would rise in an attempt to compensate and hold the blood pressure up, but after awhile the body would tire and his heart rate would fall. With his blood pressure low he would not be getting proper circulation to his brain and this would lead to disorientation. 4. It would be a very poor idea. The alcohol in the beer is a diuretic and would make him urinate more than typical.
Because we didn’t count the proper number of significant figures in the volume we had too many when we went to calculate the density. Conclusion: In this experiment we were supposed to be able to identify unknown substances using physical properties. We were successful in understanding how the use of physical properties better helps when identifying various unknown substances. Because of this experiment I learned how to take weight calculate volume density solubility and specific gravity. We were able to determine that the unknown substance was methyl by using its boiling point and other physical characteristics.