Lab Report 5

Introduction
The purpose of this experiment is to observe and predict product of oxidation-

reaction reactions and to determine the relative reactivity of a series of metallic
element. Oxidation is a loss of electron proses that occur in chemical reaction and
knows as increasing in the oxidation. For the reduction process is called by gaining
of electron in ions also being call as decreasing in oxidation state of atom, ion or
certain molecule. Those cycle also knows as redox reaction. As say in research book
“In many cases, the redox conditions can therefore not be defined by one well-
defined redox potential. The redox couples that are active at the electrode and
provides rise to an electrochemical response often might not be identical with the
predominant redox couples in solution. Measurements of individual redox species
concentrations therefore give more detailed and accurate information about the
occurring redox processes and therefore the actual redox state during a given
system”[ CITATION JSc00 \l 17417 ]
Bellow are example of redox reaction:
A reaction that involve zinc metal, features a pair of electrons at higher energy

level than an unfilled orbital within the opposite reactant, copper(II) ion. The
electrons within the upper energy orbital in zinc can spontaneously move to the
lower energy orbital in copper(II). This electron transfer could also be a redox
reaction.
As the reactant with the high energy electrons "loses" its electrons, its oxidation
state increases. during this instance , elemental zinc has an oxidation state of 0; loss
of two electrons raises its oxidation state to +2. Loss of electrons is an oxidation
reaction. Conversely, because the reactant with the low energy orbital "gains"
electrons, its oxidation state is reduced. Copper (II) has an oxidation state of +2; the
essential metal has an oxidation state of 0. Gain of electrons could also be a
reduction reaction.
In a redox reaction, the reactant that loses electrons is oxidized causes a
reduction and is known as a reducer. within the instance above, zinc metal is that the
reducing agent, it loses two electrons is oxidized and becomes Zn2+ ion. The
reactant that gains electrons is reduced causes an oxidation and is known as an
oxidant. Cu2+ ion gains two electrons is reduced to form copper metal.
In order to possess a whole , balanced redox system, there must be a minimum of
1 reduction and one oxidation, one cannot occur without the other which they're
going to occur simultaneously. For a balanced system, the quantity of electrons lost
within the oxidation reaction must be capable the quantity of electrons gained within
the reduction step. this is the main key to balancing equations for redox reactions. to
remain track of electrons, it's convenient to write down the oxidation and reduction
reactions as half-reactions. During this instance, zinc loses two electrons and copper
(II) accepts both electron.
The half-reactions for those equation are shown below:
Zn → Zn2+ + 2 e− (oxidation half-reaction, reducing agent)
Cu2+ + 2 e− → Cu (reduction half reaction, oxidizing agent)
Some metal reacts as reducing agent. To identify the reducing agent we can see by
their element is losing electron also know as oxidized. This are some common
reducing agents include metals potassium, calcium, barium, sodium and
magnesium, and compounds that contain the H− ion, those being NaH, LiH, LiAlH4
and CaH2. Some elements and compounds can be both reducing or oxidizing
agents.
Discussion
In this experiment there are two part that being separated while running whole
experiment. So also result have two part that is part A and part B. the first discussion
will be discuss is result in part A. In part A the title of the table result is Metal as
reducing agent. For the first test is on Copper reaction with three different
concentration that is 0.1 M CuSO4. The result show non-reaction, this occur because
0.1 M CuSO4 occur has a metal that is copper that is a better reducing agent that the
metal that put in solution that is also copper. In easy translate it a same element so
no reaction occurs. Copper in 3 M H2SO4 solution also show no reaction. No reaction
also occurs in third solution that is 0.1 ZnSO 4 and also no reaction occur that is zinc
is a more active reducing agent that copper. For magnesium testing in those three
solutions, first we can see a reaction in 0.1 M CuSO 4 solution that turn the
magnesium to blue solution of 0.1 M CuSO 4 turn to green solution and also appears
white bubble. For 3 M H2SO4 magnesium is dissolved completely and a ‘pop’ sound
produce. 0.1 ZnSO4 solution with magnesium added show no reaction. For zinc
metal form in 0.1 M CuSO 4 blue solution turns colourless and appears some reddish
brown on zinc metal form. Those reaction as in chemical equation is zinc sulphite
occur. For 3 M H2SO4 solution with zinc metal form, the solution become into white
precipitate and making ‘pop’ sound. For zinc metal form in ZnSO 4 solution no
reaction occurs. Next metal is steel wool, in 0.1 M CuSO 4 solution that’s is the blue
solution become turns light yellow and steel wool itself become brown. In 3 M H 2SO4
solution turn into white solution and precipitation is formed for steel wool. And ZnSO 4
solution for steel wool inside is no reaction occur. The reaction that being seen
through running the experiment in part A show a nothing non-suitable result by
following the theory that is when no reaction occurs when the metal put in the
solution, then the element form in solution is better reducing agent than the metal put
in solution. That derive from the losing and gaining ions in redox reaction.
In Part B result for solution for redox reaction, in testing 1 for 0.01 M KMnO ₄ plus 2
drops 6 M H₂SO₄ into 0.1 M Fe(NH₄)₂(SO₄)₂ show a reaction that the purple solution
change to yellow solution because of redox reaction occur in the chemical solution.
The next solution is same with testing in testing 1 but with different solution added in
it. 0.1 M K₂C₂O₄ add in the solution and being observe. The observation is no
change in the solution. The third test is 0.01 M K₂Cr₂O₇ plus 2 drops 6 M H₂SO₄
added in 0.1 M Fe(NH₄)₂(SO₄)₂ show changer that change yellow to green. Last but
not least is the same solution added to 0.1 M K₂C₂O₄ change to orange into yellow.
As in theory that redox reaction is involved a transfer of electron between element
when show two reaction that is oxidation and reduction. Finishing the equation using
half-reaction method for balancing the equation of redox reaction which required the
both element product and
References
J. Schüring, H. S. (2000). Redox: Fundamentals, Processes and Applications.

heidelberg, germany: Springer- verlaq berlin.
fundamental is same and balanced perfectly.

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Introduction

The purpose of this experiment is to observe and predict product of oxidation-

Bellow are example of redox reaction:

A reaction that involve zinc metal, features a pair of electrons at higher energy

The half-reactions for those equation are shown below:

Zn → Zn2+ + 2 e− (oxidation half-reaction, reducing agent)

Cu2+ + 2 e− → Cu (reduction half reaction, oxidizing agent)

J. Schüring, H. S. (2000). Redox: Fundamentals, Processes and Applications.

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