Redox Reaction-2282249

Lab

Purpose: The purpose of this experiment is to qualitatively analyze various redox reactions involving different metals and solutions.

Materials

MaterialsCopper sulfate (CuSO4) solutionAluminum (Al) metalZinc (Zn) metalCopper (Cu) metalSalt (for conductivity enhancement)Procedure The experiment involves qualitative analysis of redox reactions using copper sulfate solution and various metals. Four labeled beakers are prepared, each containing copper sulfate solution. Aluminum, zinc, and copper metal pieces are added to separate beakers, while one beaker remains with only the copper sulfate solution. Observations are made for each reaction, noting effervescence, color changes, and precipitate formation. Effervescence indicates gas evolution, while color changes may suggest oxidation or reduction. The absence of observable reactions in some cases indicates relative reactivity differences. The experiment aims to understand the reactivity of different metals in redox reactions and their interactions with copper sulfate solution, providing insights into chemical properties and oxidation-reduction processes.

Results

After inserting the metals in the copper (ii) sulphate solution

After 30 minutes

Data Table

Metal Solution	Observations	Redox Equations
Al + CuSO4	Effervescence; slight cloudiness; reddish-brown colour appears on the surface of aluminium metal.	2Al+3CuSO4→Al2(SO4)3+3Cu2
Zn + CuSO4	Effervescence; slight cloudiness; reddish-brown colour appears on the surface of zinc metal.	Zn+CuSO4→ZnSO4+Cu
FeCuSO4	Effervescence; slight cloudiness; reddish-brown color appears on the surface of the iron metal.	Fe + CuSO₄ → FeSO₄ + Cu
Cu + CuSO4	Solution remains blue, metal remains unchanged	No reaction

Purpose of Adding Salt: Adding salt to each of the beakers likely serves to increase the conductivity of the solution. This helps facilitate the movement of electrons during the redox reactions.

Reason for Waiting 30 Minutes: The video needed to wait for 30 minutes to allow sufficient time for the redox reactions to occur completely. Some reactions may proceed slowly, especially if the metal is less reactive or if the concentration of the solution is low.

Explanation for No Observed Reaction in the Fourth Beaker (Cu + CuSO4): In the fourth beaker involving copper wire and CuSO4, there was likely no observed reaction because copper is less reactive than the copper ions present in the solution.¹ Therefore, copper metal does not readily displace copper ions from the solution to undergo a redox reaction.

Atomic-Level Explanation for Evident Reactions

Al + CuSO4: Aluminum metal (Al) is more reactive than copper (Cu), so it displaces copper ions from the solution, forming aluminum sulfate and releasing copper metal. The reaction can be represented as: 2Al+3CuSO4→Al2(SO4)3+3Cu2Al+3CuSO4​→Al2​(SO4​)3​+3Cu

Zn + CuSO4: Zinc metal (Zn) is more reactive than copper (Cu), leading to displacement of copper ions from the solution, forming zinc sulfate and releasing copper metal: Zn+CuSO4→ZnSO4+CuZn+CuSO4​→ZnSO4​+Cu

Fe+CuSO4: Iron (Fe) displaces copper ions from copper sulfate (CuSO₄) solution due to its higher reactivity. Iron atoms oxidize to form iron (II) ions (Fe²⁺), while copper ions are reduced to elemental copper (Cu). The reaction produces iron sulfate (FeSO₄) and solid copper. This displacement confirms iron’s reactivity surpasses copper’s, illustrating a redox reaction.

Cu + CuSO4: Since both the reactant (copper metal) and the product (copper ions) are the same element, there is no net change in the oxidation state, resulting in no observable reaction.

Lab 2

Purpose: The purpose of this experiment is to determine and compare the chemical properties of three isomers of butanol (butan-1-ol, butan-2-ol, and 2-methylpropan-2-ol) and relate the observations to their molecular structure.

Materials

Materials

Butan-1-ol

Butan-2-ol

2-methylpropan-2-ol

Hydrochloric acid

Sodium metal

Potassium permanganate

Lucas regent

Pipet

Test tubes

Various beakers

Droppers

Test tube rack

Procedure

The experiment aims to compare the reactivity of three butanol isomers (butan-1-ol, butan-2-ol, and 2-methylpropan-2-ol) and correlate their observations with molecular structure. Initially, drops of each isomer are mixed with concentrated hydrochloric acid in separate test tubes to observe cloudiness, indicating alkyl halide formation. Subsequently, the isomers are reacted with sodium metal, potassium permanganate, and Lucas regent to assess their reactivity further. Sodium reactions are observed for effervescence and color changes, while potassium permanganate indicates oxidation through color changes. Lucas regent tests for the formation of an alkyl chloride. This procedure provides insights into the differing chemical behaviors of primary, secondary, and tertiary alcohols based on their structural arrangements.

Results

Before

After

Data Table: Part A

Reactants	Observations
Butan-1-ol and HCl	Cloudy
Butan-2-ol and HCl	No cloudiness
2-methylpropan-2-ol and HCl	No cloudiness

Data Table: Part B

Reactant	Observations with sodium metal	Observations with potassium permanganate	Observations with Lucas regent
Butan-1-ol	Effervescence; solution turns pink	Decolorization of permanganate; no reaction	Cloudiness observed after some time
Butan-2-ol	Effervescence; no color change	Decolorization of permanganate; no reaction	No cloudiness observed
2-methylpropan-2-ol	No reaction	No reaction	No reaction

Answers to Questions

1. Reactions with Hydrochloric Acid (HCl)

Butan-1-ol + HCl → Butyl chloride + H2O

Butan-2-ol + HCl → No reaction

2-methylpropan-2-ol + HCl → No reaction

2. Reactions with Sodium and Oxidizing Agents

Butan-1-ol + Sodium → Butane + NaOH (no reaction with oxidizing agents)

Butan-2-ol + Sodium → But-2-ene + NaOH (no reaction with oxidizing agents)

2-methylpropan-2-ol + Sodium → No reaction with sodium or oxidizing agents

3. Summary of Reactions

Halogenation: Primary alcohols (like butan-1-ol) readily undergo substitution reactions with hydrogen halides (e.g., HCl) to form alkyl halides (haloalkanes) due to the availability of the primary carbon.² Secondary alcohols (like butan-2-ol) may react but are less reactive compared to primary alcohols. Tertiary alcohols (like 2-methylpropan-2-ol) generally do not undergo halogenation due to the absence of a hydrogen atom attached to the carbon bearing the hydroxyl group.

Controlled Oxidation: Primary alcohols (like butan-1-ol) undergo controlled oxidation reactions to form aldehydes or carboxylic acids depending on the reaction conditions and the oxidizing agent used.³ Secondary alcohols (like butan-2-ol) are oxidized to ketones. Tertiary alcohols (like 2-methylpropan-2-ol) are resistant to oxidation under normal conditions due to the absence of hydrogen atoms attached to the carbon bearing the hydroxyl group.

Bibliogarphy

Grimaud A, Diaz-Morales O, Han B, Hong WT, Lee YL, Giordano L, Stoerzinger KA, Koper MT, Shao-Horn Y. Activating lattice oxygen redox reactions in metal oxides to catalyse oxygen evolution. Nature chemistry. 2017 May;9(5):457-65.

Pavlinac J, Zupan M, Laali KK, Stavber S. Halogenation of organic compounds in ionic liquids. Tetrahedron. 2009 Jul 18;65(29-30):5625-62.

Cherepakhin V, Williams TJ. Direct oxidation of primary alcohols to carboxylic acids. Synthesis. 2021 Mar;53(06):1023-34.