8. Do not eat or drink any of the liquids or substances associated in lab. PROCEDURE: I. LIQUID - Identification of an Unknown Liquid: Using the physical properties of Solubility, Density, and Boiling Point.
This experiment was performed to observe differences in density based on the chemical makeup of an object. Pennies minted before 1982, pennies minted after 1982, and an unknown metal sample was tested to see if there were any differences in their densities. Ten pennies from each category and the metal sample were weighed using a scale to find mass and the displacement method was used to find their volumes. The masses and volumes were then used to calculate the densities of the pennies (D=m/v). The density of the pre-1982 pennies were 8.6 g/mL while the post-1982 pennies were 6.9 g/mL. The metal sample’s density was 1.7 g/mL. Following the experiment we were given the real densities of each item to calculate the percent error with the formula
The purpose of this lab was to identify unknown substances using density. We had three unknown substances; a yellow liquid and two metal rods. For each substance we measured volume using the water displacement method in a graduated cylinder and mass using a triple beam balance. Then we calculated density
Calculating the percentage uncertainty for a 50 mL graduated cylinder The uncertainty of the graduated cylinder is ±0.5 mm. The volume of the substance measured is 50 mL because the density of water is 1 g/〖cm〗^3 and the mass is 1 gram per milliliter. To calculate percent uncertainty: (0.5 mm)/(50 mL)*100=1%
The purpose of the experiment is isolate the natural products -terpenes and acetogenins- and to observe their properties. The terpene used was used to isolate was limonene from a citrus peel, and the acetogenin that was used to isolate was eugenol from clove oil. The techniques used to isolate these two natural products was a steam distillation and extraction. The amount of eugenol that was recovered 2.39 grams. After the recovery of eugenol, an IR spectrum was obtained. The IR spectrum displayed the presence of an alcohol at 3529.37 cm-1 and an alkene at 1638.08 cm-1. Classification tests are used to determine what is present.The results for the classification tests for eugenol are shown below in the table.
The distillation that was more efficient at separating the two compounds was the cyclohexane and the p-xylene since the curve of the graph for temperature vs. volume has a slightly better curve (Table 4A). The graph for cyclohexane and toluene was more linear (Table 4B). Furthermore, the mole fraction of cyclohexane and p-xylene was higher than the mole fraction of cyclohexane and toluene. For instance, the mole fraction of cyclohexane and p-xylene (when adding the mole fraction of the first ml and the last couple of drops) was 0.6604 while the mole fraction for cyclohexane and toluene was 0.13396. A higher mole fraction means that the compounds were purer which means that they separated better—since increasing the mole fraction increases the vapor pressure. Therefore, my hypothesis was supported.
Determining the volume of the zinc and copper mixtures each, and record the data. Using equation get the density of the pennies. Compare the results. Find the best-fit straight line. Material: Then calculate the error%=0.01%, and the deviation%=9.74%. Weight 30 dry pre-82 pennies which get 89.77g, using 30ml initial volume measuring the volume of 30 pennies, record the data 10.0ml. Using equation Density= Mass/Volume, get the density of the pre-82 pennies is 8.98g/ml. Then calculate the error%=0.10%, and the deviation%=1.29%.
Potential error could result in when quantitatively transferring in any step and spillinng or not transferring all of any given solution. When diluting each flask has a different level for where its specific volume is, so overfilling the flask is possible when not being focused on. The condition of each penny can impact the results by if some copper was chipped off, or if anything attached to the pennies could impact test results. All of these could result in a different than desired copper percentage. It is important that the absorbance of each penny be within the range of absorbance the calibration curve has. This is because the curve created for this lab was made with 0.00 – 10.00mL of Cu^(2+)stock solution when using those values idealy this curve should therefore be 0-100% copper percentage. If values were found outside of this calibration curve then there would be problems with either calculations or a different curve would be needed to properly record
Methylcyclohexene Ashton Krstevski Lab Partner: Micheal O’Daniel Organic Chemistry 1 Laboratory, Indiana University Northwest, Gary, Indiana 46408 October 28, 2016 Abstract: The purpose of this experiment was to practice the functional group transformation procedure. The process of the experiment included the dehydration of 2-methylcyclohexanol in the presence of phosphoric acid and heat. The products that were
In the third stage of this experiment, the density of a liquid was determined and compared to known standards. A 100ml beaker was filled to about half-full with room-temperature distilled water. The temperature of the water in ◦C was recorded in order to compare to known standards later. A 50ml beaker was then weighed on a scale in order to determine mass and recorded. A sample of the distilled water with an exact volume of 10ml was then placed in the 50ml beaker using a volumetric pipette. The 50ml beaker with the 10ml of water was then weighed again and the initial mass of the beaker was subtracted from this mass to obtain the mass of the 10ml of water. With the volume and the mass of the water now known, density was calculated using d = m/V and recorded in g/ml. This process was then repeated to check for precision and compared to standard values to check for accuracy. Standard values were obtained from CRC Handbook, 88th Ed.
For example, how to physically find the density of an object by finding their mass with a balance and finding the object's volume using the method water displacement. The purpose of the experiment was to find out which metal is used to create post 1982 pennies. Pre-1982 pennies were made out of copper but then the metal used for making pennies changed. The metal used to create pre-1982 pennies was copper. Since the metal used to make pennies changed the density of post-1982 changed. The predicted density was believed to have something close to the metal zinc. Which will show that the post-1982 pennies are made out of zinc. During the experiment, the mass of the post-1982 pennies were found using an electric balance and the volume was found by water displacement. The pennies mass and volumes were recorded. After the recordings of five trials the densities was found of those each trials. After conducting the experiment by trying to find the density of the post-1982 pennies. The average density found after doing the experiment was 7.042 g/mL. The density of zinc is 7.13 g/mL. However, errors may have occurred tampering the density that was discovered. For example, reading the water measurement slightly wrong when using water displacement to find the volume of the pennies or not placing the pennies correctly in the cylinder which could create air pockets .Due to the close difference between the
Procedure: Begin this In the hood, place the copper wire in 10mL of nitric acid and wait for it to dissolve. Afterwards, add 100mL of deionized water to the solution and boil the solution, so all the nitrogen oxides are removed. Place the solution to a 250.0mL volumetric flask and add deionized water to the flask until the solution is 250.0mL. When the solution in the flask is at 250.0mL place the solution in a clean plastic bottle. Now cut a penny into four pieces, and measure the mass of all the pieces together. Go back to the hood, and place the pieces of the penny into a 250mL beaker. Afterwards, add 20mL of concentrated hydrochloric acid. Wait for the hydrochloric acid to dissolve the zinc core. When the zinc has dissolved, filter the solution through the filter paper, and place the copper metal pieces into a clean 150mL beaker. In the hood, place 4mL of concentrated nitric acid in the beaker, and when the copper dissolves add, one drop at a time, 30mL of 6 M ammonium hydroxide to neutralize the nitric acid. Transfer the copper/ammonia solution to a 100.00mL volumetric flask. Prepare four different calibration
The pennies that were dropped into the graduated cylinder could have caused some of the water to splash out of it. This may have caused an error in measuring the volume, this would have caused the volume measured to be less than the actual volume, thus allowing the density of the pennies to increase, causing the lab results to be uneven. Another source of error has to do with the mass of the pennies. After the pennies were taken out of the graduated cylinders filled with water, there was still some water droplets left on the pennies when put on the triple beam balance. This extra weight of the water may have caused the measurement in the mass of the pennies to be more than they actually were. This outcome could have caused the density of the pennies to be increased as well, making the lab results inconstant. Any type of coating, for example rust, on the penny may affect the mass. This will add to the mass making it higher, and since density is proportional to the mass, the density will be calculated higher than what it actually
Determining Mass and DensityPart A: Mass of nickel Weighing boat, nickel, a pair of forceps and chem-wipe paper were used tocarry out the experiment. Our equipment for this experiment was moved to an electronic balance inthe lab. Once the nickel was cleaned with a chem-wipe paper, it was transported intothe
There are some potential errors in both methods. For the displacement method, water could splash out of the graduated cylinder causing the density to be inaccurate and lower than the actual density. For the floatation method, the object could float long enough to get the measurement and report findings, but there could be a pocket of glycerin or ethanol that was not dispersed therefore causing the findings to be inaccurate, density could therefore be too high or too low.