Preview

Pre Lab Experiemnt 8

Powerful Essays
Open Document
Open Document
754 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
Pre Lab Experiemnt 8
Student: Krystianna Platz Date: November 5, 2014 Section: 113 R- 8AM Experiment 8
Determination of Percent Composition of Pennies Using Redox and Double Displacement (Precipitation) Reactions
Objectives: The lab experiment will consist of oxidation-reduction and double displacement reactions as well as titration techniques. All these components will be used in order to determine the percent composition of pennies. In conducting redox and double displacement we are able to analyze a penny and figure out the chemical composition of the product. The experiment entails careful observations and recording of evidence for a chemical reaction. In this experiment observe gases being produced, the forming of precipitation and color changes.

Questions:
1. What is the weight of a post 1982 penny?
- Approximately 2.496 grams
2. What is the percent copper and zinc in a post 1982 penny?
- 97.5 % Zinc and 2.5 % Copper
3. How many grams of copper and zinc are in a post 1982 penny?
- (2.496 x 0.975) = 2.43 g of Zinc (2.496 x 0.025) = 0.062 g of Copper
4. How many moles of copper and zinc are in post 1982 pennies?
(2.43 g Zn x 1 mol Zn) / 63.38 g Zn = 0.037 mol Zn
(0.062 g Cu x 1 mol Cu) / 63.54 g Cu = 0.00097 mol Cu
5. Write a balanced reaction of zinc with HCl.
- Zn (s) + 2HCl (aq)  ZnCl2 (aq) + H2 (g)
6. How many moles of HCl are needed to react completely with all of the zinc in a post 1982 penny?
(2.43 g Zn x 1 mol) / 65.38 g Zn = 0.037 mol Zn
(0.037 mol Zn x 2mol HCl) / 1 mol Zn = 0.074 mol HCl is needed
7. In a procedure developed to determine the percent zinc in post 1982 pennies, 50 ml of an HCl solution was used to react (dissolve) all of the zinc in the penny. To ensure complete reaction, the solution contains twice as many moles of HCl that is actually needed. What concentration of HCl should be used?
- (0.074 mol HCl / 0.05 L) = 1.48 M
8. In the scenario described in

You May Also Find These Documents Helpful

  • Good Essays

    Chm 130 Lab 7

    • 1376 Words
    • 6 Pages

    3. Calculate moles of zinc based on original mass of zinc. Show your calculations. (20 points)…

    • 1376 Words
    • 6 Pages
    Good Essays
  • Good Essays

    Penny Lab Report

    • 674 Words
    • 3 Pages

    The experiment will be using HCl a strong acid to dissolve all the zinc inside the outer copper shell. The reaction follows as such; Zn+2HCLZnCl2+H2, but there will be no reaction with copper. The portion that will be measured is the mass of copper left after all of the Zn goes through the reaction process.…

    • 674 Words
    • 3 Pages
    Good Essays
  • Good Essays

    H. How would you prepare 10 mL of a 0.25M HCl solution if 1M HCl was available? How much…

    • 412 Words
    • 2 Pages
    Good Essays
  • Good Essays

    Cu of a post 1982 penny

    • 916 Words
    • 5 Pages

    Before 1982 the US penny was made of pure copper. Because of the high cost of copper, the US government changed the composition of the penny. As of 1982, pennies have been made of mostly zinc, with a thin copper layer on the outside. The first step in finding the % of copper is to make solution out of the penny. In other words “liquefy” the penny. To differentiate between the copper and zinc; zinc is clear and copper turns blue. During this lab, we will be making several standard solutions of this penny solution. To find out each solutions concentration, we will find its molarity by using the formula:…

    • 916 Words
    • 5 Pages
    Good Essays
  • Satisfactory Essays

    5.04 Honors lab Chemistry

    • 428 Words
    • 5 Pages

    n = 1.074 atm x 0.03 L / 0.0821 x 295.15 K = 0.00133 mol H2…

    • 428 Words
    • 5 Pages
    Satisfactory Essays
  • Satisfactory Essays

    Chm Lab

    • 415 Words
    • 2 Pages

    6.33 g CO2 * 1 mol CO2 44.10 g CO2 * 1 mol NaHCO3 1 mol CO2 *84.20 g NaHCO3 1mol NaHCO3 =12. 1 g NaHCO3…

    • 415 Words
    • 2 Pages
    Satisfactory Essays
  • Good Essays

    Penny Lab

    • 522 Words
    • 3 Pages

    Background Information: Post-1983 pennies have a copper jacket and a zinc core. We hope to determine the percent composition of these two metals. This will be done by reacting the zinc with hydrochloric acid to form zinc ions in a single replacement reaction. The acid reacts with the zinc but not copper. The reaction of zinc metal with the hydrochloric acid (HCl) produces zinc chloride and hydrogen gas. Safety: Wear your safety goggles and apron If you spill Hydrochloric acid on yourself, rinse with water Procedure: DAY I 1. Take a post-1983 penny and, using a triangular file, etch an “X” on one side of the penny. Also etch a notch on the edge of the penny in the four positions shown in the diagram. 2. Mass and record the mass of the penny. 3. Using a graduated cylinder, measure 60.0 mL of 3.0 M HCl and pour it into your 100mL beaker. 4. Place the penny in the HCl solution etch side up and record observations for 3-5 minutes. 5. Place the beaker in your lab drawer. 6. Answer question #1 for tomorrow. Read and prepare a data table for Day II. DAY II 1. Using your forceps, carefully remove the fragile copper jacket that is left from the penny. Rinse it gently in distilled water. 2. Dry the penny in acetone solution. Swirl the penny in the solution. 3. Pour the acid solution from your beaker into the waste container at the center table. Rinse and dry your beaker. 4. Take a magic marker and write your lab drawer number on the side of your 50 mL beaker. 5. Place the penny in the beaker and put the beaker on the appropriate shelf of the drying oven. DAY III 1. Mass and record the mass of the dry copper jacket. 2. Complete the questions and calculations for tomorrow.…

    • 522 Words
    • 3 Pages
    Good Essays
  • Satisfactory Essays

    Experiment 4a

    • 440 Words
    • 2 Pages

    The purpose of this lab is to create an experiment where zinc reacts with hydrochloric acid in order to find out the number of moles and atoms of zinc reacted. This can be accomplished by weighing the sample before and after the reaction with hydrochloric acid.…

    • 440 Words
    • 2 Pages
    Satisfactory Essays
  • Satisfactory Essays

    5.8 x 10-2 g AgCl X 1 mol AgCl X 1 mol NaCl X 58.44 g NaCl = 2.365 x 10-2 g NaCl…

    • 218 Words
    • 2 Pages
    Satisfactory Essays
  • Good Essays

    Oxidation involves the gain of electrons of hydrogen or the loss of oxygen or decrease in oxidation state. If zinc completely reacts with HCL, then the theoretical yield of copper should be equivalent to the actual yield.…

    • 623 Words
    • 3 Pages
    Good Essays
  • Satisfactory Essays

    7.56 g x 1 mol x 6.02 x 1023 molecules = 2.85 x 1022 molecules…

    • 753 Words
    • 3 Pages
    Satisfactory Essays
  • Better Essays

    Lab Penny Ante 2

    • 1080 Words
    • 4 Pages

    3. Obtain two containers to hold the pennies. Label one container R, for reactants, and the other container P, for products.…

    • 1080 Words
    • 4 Pages
    Better Essays
  • Satisfactory Essays

    LAB 20C

    • 561 Words
    • 3 Pages

    3. Molarity of HCl = 5.26 x 10-3 mol / 0.010 L = 0.526 M…

    • 561 Words
    • 3 Pages
    Satisfactory Essays
  • Satisfactory Essays

    Lab 3 Requirements

    • 280 Words
    • 2 Pages

    0.72 g Na2C03 x 1 mol Na2C03 x 1 mol CaC03 x 100 g CaC03 =…

    • 280 Words
    • 2 Pages
    Satisfactory Essays
  • Good Essays

    Weight the mass for the different percent of zinc and copper mixtures, which have 11 groups.…

    • 1204 Words
    • 4 Pages
    Good Essays