G.C.1-1 Density Lab Report-1 PDF

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G.C.1-1 Identification of Metals and Unknown Liquid Density Lab Report Name: Stephanie Sandler Z Number: Z23552088

Summary of the Video: There’s multiple metals and you have to find the density of that metal from their density. To start off the experiment, you need a scale, a graduated cylinder, an unknown metal, a weight boat to weigh your metal in the scale, and distilled water. First, you need to start to measure the mass of the unknown metal. Next, you open up the scale and record your initial amount for the weighing boat. Then, you transfer some amount of metal and add that to the weight boat. Now we know the initial mass of the weight boat and the final mass made both together with metal, so we can calculate the mass of the metal. Secondly, a certain amount of water is transferred to graduated cylinder and you record. An example is 15 mL of water being transferred with a 25 mL graduated cylinder or above recommended. Then, the initial volume of the water is recorded from the meniscus, which is 15 mL (milliliters), and the metal is dropped off. After the metal is dropped, the new reading is now 17 mL, which is recorded. So now we know the mass and volume of the metal. The amount of volume replaced by the metal is the volume of the metal. Next, you look at the list given to you and find the unknown density of the metal. For the second part of the lab, it’s required to use a volumetric flask to measure the amount of liquid for the unknowns. Next, you get your unknowns and transfer them to a volumetric flask. If you have a 250 mL volumetric flask, you will transfer 250 mL of unknown solution to the flask. Then, you will use a scale to measure the mass of the liquid solution. After that, you do the same steps with the second unknown, use the same volumetric and numbers of the flask and transfer the same amount of second unknown and measure the mass. If you know the mass and volume of the liquid, you can find the density.

Metal Density Problem: Use measurements made in the virtual lab to determine the density of unknown metals (metal 1, metal 2, and metal 3). The density will be used to determine the identity of the metal. You will find the name of the metal from the unknown list which are given below: Table of Unknown Metals: Metal Copper Silver Aluminum Platinum Zinc Rhodium

Density (g/cm3) 8.92 10.49 2.65 21.45 7.13 12.4

Reminder: For this lab, you need to watch the video (to know how to navigate the program) and understand the concept of the lab (for example: what is density and how do we measure density?) Do not be afraid to play with the program, it is a user friendly program and if you want to remove/empty something, right-clicking gives you the option to do so. This also means it might take you some time to get used to the program, so please do not wait until the last minute to complete the virtual labs.

Procedure: 1. You will need scale, weight boat, graduated cylinder (use the 25 mL or larger one) and water. The program is drag and drop. For instance, you place the weigh boat on the scale, it will tell you a number, so record that in your worksheet. Then pick an unknown sample as you drag it over the weight boat, it will give you the option to pour. 2. This lab emulates real life scenarios so that means you cannot pour an exact amount. By lightly clicking “Hold to pour just once, and it will give you the weigh boat and metal mass total on the scale. 3. To measure the volume of the metal pieces, fill your graduated cylinder about half full with water. Take a reading and record the volume, then drop your metal in the water and record final water volume. The key is to follow the lab worksheet and as you work through, the flow of the worksheet guides you through the lab. 4. The mass/volume relationship that will allow you to determine density of the unknown metal, and you have to find the identity of the metal from the given table.

Density worksheet Data (points shown/data collected) Mass of weighing dish (g) Mass of weighing dish and sample (g) Mass of sample (g)

Sample #1 4.3280 g 9.5904 g

Sample #2 5.5320 g 10.8311 g

Sample # 3 4.4792 g 20.7986 g

(2) – (1) = 5.3 g

(2) – (1) = 5.3 g

Volume of water (mL) Volume of water and metal (mL) Volume of metal sample (mL) Density of metal sample (g/mL) Identity of metals

15.0 mL 16.0 mL 1.00 mL 5.3 g/mL Germanium

15.0 mL 16.0 mL 1.00 mL 5.3 g/mL Germanium

(2) – (1) = 16.3 g 15.0 mL 17.0 mL 1.5 mL 11 g/mL Technetium

List of Equipment and Glassware with sizes: 25 mL graduated cylinder, H2O distilled water with 3.0 L (liters), a scale, one metal, a weight boat with 0.0877 L (liters).

Calculations: Show all your calculations by using correct significant figures and units.

9.5904 g – 4.3280 g = 5.3 g (mass of sample) 5.3 g / 1.00 mL = 5.3 g/mL (density of metal sample)

10.8311 g – 5.5320 g = 5.3 g (mass of sample) 5.3 g / 1.00 mL = 5.3 g/mL (density of metal sample)

20.7986 g – 4.4792 g = 16.3 g (mass of sample) 16.3 g / 1.5 mL = 11 g/mL (density of metal sample)

Unknown Liquid Density Problem: You work for a company that has many different research groups, and your group has just developed a new food preservative which has been named “Compound A”. Another group in your company has developed a new neurotoxin, which they have unfortunately also called “Compound A”. An intern was reorganizing the chemical storage stockroom, and placed all the bottles labeled “Compound A” on the same shelf. You would like to begin testing the new food preservative, do not know which bottle contains the food preservative and which contains the neurotoxin. It would clearly not be a good idea to put neurotoxin into your food products. You have asked a theoretical chemist what to do, and he said that the preservative will have a higher density.

1. Design an experiment to determine which bottle of “Compound A” contains the food preservative. 2. Give a detailed description of how you determined the densities of the two compounds (describe equipment and amounts used; you have to show calculations, but give the weights and volumes found and how you measured them). Please see attached rubric for the virtual lab activity. You do not need to construct table for this problem. Note: Precise transfer mode have been disabled for this activity, you may find a volumetric flask and scale useful in performing this experiment.

List of Equipment and Glassware with sizes: 250 mL volumetric flask, scale, bottle 1 of compound A and bottle 2 of compound A.

Procedure (Give a detailed description of how you determined the densities of the two unknown compounds): 1. You will need 250 mL of a flask and scale. 2. Measure the mass of the flask alone by placing it onto the scale and record the mass. Then remove the mask from the scale. 3. Select the unknown sample of liquid, drag and drop it to the flask and hold the button “hold to pour” to pour it all into the flask. Below the button “hold to pour” the volume of the sample will appear. Then record the volume.

4. Place the flask containing the unknown liquid on the scale and measure the mass in. The subtract the mass of the empty flask from the mass of the flask and unknown liquid to get the mass of the unknown liquid and record the mass. 5. Find the density by dividing mass over volume. Make sure to include the right significant figures and the right units.

Calculations, use correct significant figures, and include units: Mass of metal = mass of dish and metal – mass of dish -Compound A1: - Mass of flask = 96.7963 g -Mass of flask and Compound A1 = 277.6157 g 1) Mass of flask and Compound A1 – mass of flask = 277.6157 g – 96.7963 g = 180.8194 g -Mass of Compound A1 = 180.8194 g -Volume of Compound A1 = 12.37 mL 2) Density = mass/volume 180.8194 g / 12.37 mL = 14.62 g/mL -Density of Compound A1= 14.62 g/mL (This is the food preservative)

-Compound A2: -Mass of flask = 94.6027 g -Mass of flask and Compound A2 = 114.6411 g 1) Mass of flask and Compound A2 – mass of flask = 114.6411 g – 94.6027 g = 20.0 g -Mass of Compound A2: 20.0 g -Volume of Compound A2 = 16.83 mL 2) Density = mass/volume 20.0 g / 16.83 mL = 1.20 g/mL -Density of Compound A2 = 1.20 g/mL...