Name: Zachary McMorrough.
Lab Partner: Don’t need.
Course: CHM 120 Lab Section 1.
Title: Copper from Start to Finish: A Sequence of Chemical Reactions.
Date: 10/8/2015
Purpose: The purpose of the lab was to perform a series of chemical reactions in order to transform copper within different reactions in order to start and end with solid brown copper.
Pre-Lab Questions:
a. The acid is toxic when combustion occurs and can be harmful if inhaled.
b. Acids become much more toxic and lethal when concentrated.
a. - Provides OH ions needed to precipitate Cu(OH)2
- Neutralize the acid.
b. When the reaction is basic, then the Cu(OH)2 precipitation is complete.
a. Litmus test.
b. When the litmus paper turns blue, then it is more basic.
…show more content…
c.
The Mg is added until the gas bubbles stop.
d. Litmus test.
91.89% recovery. b/c .34g/.37g x 100
Results:
Oxidizing Cu with Concentrated HNO3 Solution
Chem Equation: Cu(s) + 4HNO3(aq) → Cu(NO3)2(aq) + 2NO2(g) + 2H2O(l)
Ionic Equation:
Cu(s) + 4H+(aq) + 4NO3(aq) → Cu2+(aq) + 2NO3(aq) + 2NO2(g) + 2H2O (l)
Colors: Brown solid Cu to aqueous blue copper liquid
Net Ionic Equation: Cu(s) → Cu2+(aq)
RXN Type: Oxidation
Precipitating Cu(OH)2 with NaOH Solution
1
Chem Equation: Cu(NO3)2 (aq) + 2NaOH (aq) → Cu(OH)2 (s) + 2NaNO3 (aq)
Ionic Equation:
Cu (aq) + 2NO3 (aq) + 2Na+ (aq) + 2OH- (aq) → Cu(OH)2 (s) + 2Na+ (aq) + 2NO3(aq)
Colors: blue liquid to a blue gel
Net Ionic Equation: Cu2+ (aq) → Cu(OH)2 (s)
RXN Type: Double Displacement
2
Chem Equation: HNO3(aq) + NaOH(aq) → NaNO3(aq) + H2O(l)
Ionic Equation: H+(aq) + NO3(aq) + Na+(aq) + OH-(aq) → Na+(aq) + NO3(aq) + H2O(l)
Net Ionic Equation: H+ (aq) + OH- (aq) → H2O(l)
RXN Type: Acid-Base
Neutralization
Using Heat to Convert Cu(OH)2 to CuO
Chem Equation: Cu(OH)2 (s) → CuO(s) + H2O(l)
Colors: blue gel to black solid powder
D. RXN Type: Decomposition
Dissolving CuO with H2SO4 Solution to Form [Cu(H2O)6]+2 Ions
Chem Equation: CuO (s) + H2SO4 (aq) → CuSO4 (aq) + H2O (l)
Colors: black solid to blue liquid
D. RXN Type: Double Displacement
Reducing [Cu(H2O)6]+2 to Cu with Mg
1
Chem Equation: CuSO4(aq) + Mg(s) → Cu(s) + MgSO4(aq)
Ionic Equation: Cu2+(aq) + SO42-(aq) + Mg(s) → Cu(s) + Mg2+(aq) + SO42-(aq)
Colors: Blue liquid to clear liquid with bubbles
Net Ionic Equation: Cu2+(aq) + Mg(s) → Cu(s) + Mg2+(aq)
RXN Type: Redox
2
Chem Equation: Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
Ionic Equation: Mg(s) + 2HCl(aq) → Mg2+ (aq) + 2Cl- (aq) + H2(g)
Colors: clear liquid with bubbles added red-brown particles.
Net Ionic Equation: Mg(s) + 2HCl(aq) → Mg2+(aq) + H2(g)
RXN Type: Redox
Cu Recovery:
Starting Cu Mass: 0.389 g Cu
Ending Cu Mass: 0.373 g Cu
.373g/.389g x100% = 95.89% recovered.
This is a fairly good yield. Some mass could have been lost from decanting the Cu after step 3 in the lab.
Post-Laboratory Questions:
a. The solution would have stayed acidic and the litmus paper wouldn’t have changed to a blue color. This is because HNO3
Al to Al(OH)4 – (aq). Cut and Measure approximately one gram of aluminum off the side of a soda can. Take a piece of stainless steel scouring pad to remove the coating from both sides of the aluminum. Cut the Aluminum into smaller pieces to increase the surface area so the rate of the chemical reaction can increase and dissolve more quickly. Reweigh the aluminum to determine its exact mass. In a hood, add the aluminum to a 400mL beaker containing 50mLs of KOH potassium hydroxide. Allow the solution to sit until all of the aluminum has dissolved. This process could take up to 20 minutes. You may also need to use a low heat setting on a hot plate. During the reaction, the product will turn a dark grey color. The reaction is complete once all of the aluminum has dissolved and hydrogen gas ceases to evolve. After the aluminum has dissolved use gravity filtration to remove all solids from the solution, collect the solution into a 250 mL Erlenmeyer
In this case, the nitrate ion moved from one compound to another as the Cu was replaced by Zn. The zinc dissolved to form zinc (II) ions as the copper (II) ions came out of the solution as copper metal and deposited on the surface of the
The equation shows how 1 mol of Na2CO3 reacts with 1 mol of H2SO4, so
Introduction: The purpose of this lab was to cycle solid copper through a series of chemical forms and return it to its original form. A specific quantity of copper undergoes many types of reactions and goes through its whole cycle, then returns to its solid copper to be weighted. We observed 5 chemical reactions involving copper which are: Redox reaction (which includes all chemical reactions in which atoms have their oxidation state changed), double displacement reaction, precipitation reaction, decomposition reaction, and single displacement reaction. 4HNO3(aq) + Cu(s) --> Cu (NO3)2(aq) + 2H2O (l) + 2NO2(g) Oxidation reduction reaction Cu (NO3)2(aq) + 2 NaOH (aq) --> Cu (OH)2(s) + 2 NaNO3(aq) Precipitation Reaction Cu (OH)2(s) + heat --> CuO (s) + H2O (l) Decomposition reaction CuO (s) + H2SO Data Results: (mass of copper recovered / initial mass of copper) x 100 Mass of copper recovered: 0.21 Initial mass of copper: 0.52 (0.21/0.52)x100 =40.38%.
Copper II Sulfide ~ (final mass of compound) _ç3.07g - 2.59gç_ x 100 = 15.6%
In this experiment, the mass of copper and zinc is needed in order to receive its percent composition. To start off the experiment, the penny is from 1982 since the article was based off the 1982 pennies. The penny’s mass is weighed before the copper is scraped off the surface. By taking the mass beforehand, the total mass of the penny is used in the percent composition calculation. Also, scraping off the bits of the copper will expose the zinc to the hydrochloric acid since the zinc will react to the acid. The penny and the acid will be left in a beaker overnight to give the reactants more time to react. The reactants will form into aqueous, leaving only copper as a solid in the acid because the copper won’t react with the hydrochloric acid
== == I completed a table to show my results, here is the table: Table 1. Results of different changes of substances Part A Copper (II) Sulfate and Water Reactant description Water (reactant): Color: Colorless Transparency:
The concentrate is dried and sent into a reverberatory furnace. The minerals are partly oxidized and melted, resulting in isolated layers. The matte layer refers to the iron-copper sulfide mixture which sinks to the bottom. The slag, which refers to the remaining impurities, floats on top of the matte and the discarded. Sulfur dioxide gases are also collected and made into sulfuric acid for use in hydrometallurgical leaching. The matte is recovered and moved to the converter, a cylindrical vessel into which the copper is poured. Air, lime and silica are added to react with the metal oxide. The slag is removed and the Sulfur dioxide and converted into sulfuric acid, this forms blister copper which is 97-99% pure.
Na2 S2 O3 (aq) + 2HCl (aq) à 2NaCl (aq) +H2O (l) + SO2 (aq) +S (s)
A precipitation reaction can occur when two ionic compounds react and produce an insoluble solid. A precipitate is the result of this reaction. This experiment demonstrates how different compounds, react with each other; specifically relating to the solubility of the compounds involved. The independent variable, will be the changing of the various chemical solutions that were mixed in order to produce different results. Conversely the dependent variable will be the result of the independent variable, these include the precipitates formed, and the changes that can be observed after the experiment has been conducted. The controlled variable will be the measurement of ten droplets per test tube.
= 3 ´ E(C-H) + 1 ´ E(C-O) + 1 ´ E(O-H) + 1.5 ´ E(O=O)
Na2S203 (aq) + 2HCl (aq) -> 2NaCl (aq) + H20 (l) + SO2 (g) + S (s)
The aim of this investigation was to determine how five different metals of differing reactivity reacting with Copper Sulfate solution would affect the enthalpy change of the reaction.
3TiO2 (s) + 4C (s) + 6Cl2 (g) ↔ 3TiCl4 (g) + 2CO2 (g) + 2CO (g)
Rate of Reactions Gemma Cockle 9F. The Title of the Report: YOUR NAME: Gemma Cockle YOUR PARTNERS NAMES: Grace O’Sullivan and Georgia Rasch YOUR TEACHER’S NAME: Mr Walters CLASS: 9F DATE OF EXPERIMENT: 09/05/14 DUE DATE: 20/05/14. Aim: To investigate what factors affect the rate of a chemical reaction.