Julene Thai 06/10/15 CHM 120-5 Sequencing copper chemical reactions Purpose: To see how much copper can be recovered after a series of chemical transformations. Pre-Laboratory Assignment: (a) It must be carried out under a fume hood because the oxidation of Cu with HNO3 solution produces NO2 gas, which is toxic. (b) One should be particularly careful when using concentrated HNO3 solution because it is highly toxic and an oxidant. (a) The NaOH solution neutralizes the H3O ions and provides hydroxide ions needed to precipitates Cu(OH)2. (b) It is important for the final solution to be basic so that the red litmus paper can react and turn blue. (a) The litmus test will be performed to determine when there has been sufficient NaOH solution added …show more content…
(c) One can determine that they have added sufficient Mg in Reaction V by adding additional amounts until the gas bubbles stop forming. (d) A litmus test will be performed to determine whether or not the Mg in the reaction has completely reacted because the paper’s blue color will disappear once the reaction is over. The student’s mass percent recovery of Cu is 91.89% which is found by dividing 0.34g by 0.37g and multiplying the answer by 100%. Results: Chemical Reactions: Chemical equation: Cu(s) + 4HNO3(aq) → Cu(NO3)2(aq) + 2NO2(g) + 2H2O(l) Ionic: Cu(s) + 4H+(aq) + 4NO3(aq) → Cu2+(aq) + 2NO3(aq) + 2NO2(g) + 2H2O(l) Net ionic: Cu(s, red-brown) Cu2+(aq, blue) Reaction type: Oxidation Chemical equation: Cu(NO3)2(aq) + 2NaOH(aq) → Cu(OH)2(s) + 2NaNO3(aq) Ionic: Cu(aq) + 2NO3(aq) + 2Na+(aq) + 2OH-(aq) → Cu(OH)2(s) + 2Na+(aq) + 2NO3(aq) Net ionic: Cu2+(aq) Cu(OH)2(s, blue gel) Reaction type: Double replacement Chemical equation: HNO3(aq) + NaOH(aq) → NaNO3(aq) + …show more content…
Ionic: H+(aq) + NO3(aq) + Na+(aq) + OH-(aq) → Na+(aq) + NO3(aq) + H2O(l) Net ionic: H+(aq) + OH-(aq) → H2O(l) Reaction type: Neutralization Chemical equation: Cu(OH)2(s) ∆ CuO(s, black powder) + H2O(l) Reaction type: Decomposition Chemical equation: CuO(s, black powder) + H2SO4(aq) → CuSO4(aq) +
The Cu Later lab experiment is designed to allow you to practice lab skills in implementing and performing a series of reactions. Specifically, four types of chemical reactions will occur: oxidation/reduction; double replacement; single replacement; and decomposition. You will begin with a known amount of copper metal, which, after progressing through several steps, is reproduced. In this experiment you will observe and record the various changes such as heat, color changes, and production that occur. This procedure is used to observe some chemical reactions of copper and its compounds while also performing the lab appropriately as to retain the copper as much as
-If the copper metal is submerged in the silver nitrate solution then in reaction, a pure, solid (Ag) silver product is created with an excess of (Cu (NO3)2) copper (II) aqueous liquid because a single displacement reaction occurs where the balance equation is then
The objective of this lab was to use prior knowledge about the Law of Conservation of Matter and of different types of chemical reactions in order to evaluate if aluminum disappears during the reaction and copper appears. The reaction that occurred between Copper (II) Chloride and aluminum was a single replacement reaction. Clear signs that a chemical reaction took place include heat release/temperature change, color change, and formation of a precipitate. When a single element, in this instance aluminum, replaces another element in a compound, copper, a single replacement reaction occurs. A basic formula for these reactions is AB + C → AC + B.
The lab performed required the use of quantitative and analytical analysis along with limiting reagent analysis. The reaction of Copper (II) Sulfate, CuSO4, mass of 7.0015g with 2.0095g Fe or iron powder produced a solid precipitate of copper while the solution remained the blue color. Through this the appropriate reaction had to be determined out of the two possibilities. Through the use of a vacuum filtration system the mass of Cu was found to be 2.1726g which meant that through limiting reagent analysis Fe was determined to be the limiting reagent and the chemical reaction was determined to be as following:-
3. Find the number of atoms of each of the substances involved in the reaction.
The Copper Cycle is a popular experiment used to determine if an element, in this instance, copper, reverts to its elemental form after a chain of reactions. This experiment is very dangerous because of the reactions between the strong acids and bases. In this experiment I performed a series of reactions starting with copper metal and nitric acid to form copper (II) nitrate. Then I reacted copper and several other solutions such as, sodium hydroxide, sulfuric acid, ammonium hydroxide, and hydrochloric acid to form precipitates. In conclusion my percent recovery
The Oxidation of a Secondary Alcohol with Sodium Hypochlorite experiment was performed to show how to change an unknown alcohol into a ketone. The unknown that was found for this experiment was Compound A. Once the ketone was found from the unknown alcohol, an IR and the boiling point was taken to try and figure out what the product and starting alcohol actually is. The first thing that is added to the 1.50 g of unknown compound A is 15 mL of 8.25% of NaOCl, which is a bleach solution. This reacted with the alcohol so the solution could then be tested using the iodide-starch paper. The reaction came out positive when tested because a blue, black spot appeared on the strip.
The purpose of the experiment is to cycle solid copper through a series of five reactions. At different stages of the cycle, copper was present in different forms. First reaction involves reaction between the copper and nitric acid, and copper changed from elemental state to an aqueous. The second reaction converted the aqueous Cu2+ into the solid copper (2) hydroxide. In the third reaction Cu(OH)2 decomposed into copper 2 oxide and water when heated. When solid CuO reacted with sulfuric acid, the copper returned to solution as an ion (Cu2+). The cycle of reactions was completed with the reaction where elemental copper was regenerated by Zn and Cu
It is a chemical reaction where the colors of both solution and iron strip changed. It is
Copper starts to dissolve and bubbling occurs when nitric acid was added. The solution became green and the beaker started to become orange/brown as gas was being released. Solution then became light blue when washed with water.
Purpose: The purpose of this experiment was to observe the many physical and chemical properties of copper as it undergoes a series of chemical reactions. Throughout this process, one would also need to acknowledge that even though the law of conservation of matter/mass suggests that one should expect to recover the same amount of copper as one started with, inevitable sources of error alter the results and produce different outcomes. The possible sources of error that led to a gain or loss in copper are demonstrated in the calculation of percent yield (percent yield= (actual yield/theoretical yield) x 100.
Part A.1. Sodium metal is also readily oxidized by oxygen. If the product of the reaction were dissolved in water, what would be the color of the litmus for a litmus test? Explain. What is the product?
Before the synthesis of the Copper Iodine Compound, the identities provided (CuNO3)2 and Nal weighed 1.65 g and 4.7 g, respectively. After being weighed, the (CuNO3)2 exhibited a blue color, while the Nal, through observation, was a white color. However, when both identities were combined, the product turned into a brown and red rocky material. Once 20 mL of deionized water was added, the product quickly turned pale pink paste. After the solution was repeatedly washed with a total of an additional 100 mL of deionized water, the product was powdery and pink with small grains, and was left to air-dry. Once the product was air dried, it was observed to be a pale pink color, while the filter paper was stiff as the product was hard and dry. Therefore, the solid was scraped off onto a recrystallizing dish. However, the mass of an empty recrystallizing dish needed to be recorded in order to compare how much of the synthesized copper iodide was obtained. Within this case, the empty recrystallizing dish used weighed 32.01 g, the product on the empty dish weighed 1.03 g, having a total weight of 33.04 g.
At the end of the experiment when the lid was removed, it was found out that the blue colour of the copper (II) sulphate solution has faded away. It was turned to pale grey and there were some precipitates present. It was the zinc powder that was in excess to ensure that the copper (II) sulphate solution could react fully with the zinc powder.
Copper Equation: Cu2+ + 2OH- Cu(OH)2 Sodium hydroxide test – few drops of sodium hydroxide are added to a solution of a metal compound. Light blue precipitate is formed Nickel Equation: Ni(s) + 2H+(aq) + SO42-(aq) Ni2+(aq) + SO42-(aq)