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lOMoARcPSD|19384520

Virtual Lab Manual
Titration: Neutralize an acid lake
contamination  
Synopsis
Counting potatoes in a bag would be pretty easy
...

Now imagine counting the amount of acid in a water sample
...
With appropriate lab
apparatus, a chemical indicator and a base solution, you can determine the concentration
of any acid
...
You will need a burette, a stand, a
clamp and a flask to begin the titration procedure
...
In this simulation, we will help you ace the assembly
process so that once you go to the real-life lab, you will be able to recognize and explain
the function of each part of the apparatus used in the titration technique
...
But in science, many
repetitions doesn’t always lead to improved accuracy
...
You also have the
freedom to experiment with multiple indicators, various sample and titrant volumes
...
You can try to do the analysis yourself or let us guide you through the analysis,
where you’ll go through the method of determining the concentration of the acid step-bystep
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com)

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All Rights Reserved

lOMoARcPSD|19384520

Will you be able to perform the titration and calculate the acid concentrations?

Learning Objectives
At the
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●
●
●
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end of this simulation, you will be able to…
Assemble the apparatus required for titration
Describe the function of each part of the titration apparatus
Explain the general steps of a colorimetric acid-base titration and its uses
Perform a titration experiment
Describe the role of the 3 main reagents used in a titration: sample, titrant, and
indicator
● Explain what is the endpoint of a titration and the role of the indicator
● Explain why the use of high-precision volumetric material is essential for a titration
● Calculate the concentration of the titrated solution from the results of the titration
experiment

Techniques in Lab
● Acid-base titration

Theory
Titration
Titration is a technique to measure the concentration of an acid or alkali in a sample, by
comparing it to the concentration of an alkali or acid in a standard solution
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1: The burette is filled with a standard solution; 2: A clamp
holds the burette; 3: The flask contains a solution of unknown concentration and indicator
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● Volumetric flask: makes up an accurate volume of a solution
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A: Volumetric flask; B: Bulb
pipette; C: Burette
Before their use, the burette and pipette are cleaned and rinsed with the solution they will
eventually contain
...

How to perform titration

Prepare the unknown concentration solution
● Place the unknown concentration solution in a conical flask using a calibrated

pipette
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Prepare the standard solution
● Fill a clean burette with the standard solution
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● The solution should be added dropwise from the burette while continually swirling

the flask when the end-point is close
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Prepare for analysis
● Repeat titration until concordant titres are achieved
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Reading the burette
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Swirling: It is important to keep a titration well mixed, so the acid and alkali can
rapidly contact each other
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Finding the concentration of a solution
We require the following information to determine the concentration of a solution:
● The balanced equation for the reaction
● The volume of the solution with an unknown concentration in the conical flask
● The volume of standard solution in the burette
● The concentration of the standard solution in the conical flask

Work example
Problem:
An acid-base titration is performed to find the concentration of sodium hydroxide
...
0 mL
of a solution of sodium hydroxide is neutralized by exactly 24
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250 mol/L
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What we know:
Reaction: NaOH + HCl → NaCl + H2O
Moles (mol)
Concentration (mol/L)
Volume (mL)

NaOH
x
x
50

HCl
x
0
...
50

Step 1
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25 x 24
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006125 mol
Step 2
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The
balanced equation shows that 1 mol of NaOH reacts with every 1 mol of HCl
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006125 mol
Step 3
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All Rights Reserved

lOMoARcPSD|19384520

Concentration (mol/L) = number of moles of solute (mol)/ volume of solution = 0
...
123 mol/L
Additional step
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123 x 10 = 1
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Glossary for titration simulation
● Acid: species that donates a proton in aqueous solution
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● Alkali: species that accepts a proton in aqueous solution
● Concordant titre: the volume of two or more titres that are similar in quantity (less
than a 0
...

● Dilution: the process of reducing the concentration of a solute in solution, usually by
mixing it with more solvent
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● Indicator: a dye or mixture of dye that marks the end-point of the titration
...

● Rough titration: it is used along with the first titration to get an approximation
volume that is needed to reach the end-point
...

Unit Conversion
The International System of Units (SI) is a globally agreed on a system of units
...
The
table below helps you to convert the unit you encounter in the simulation
...
001 m3 =
1000 cm3 = 1000 ml
molar
M
molarity
or
molar
1 M = 1 mol/L = 1
concentration
mol/dm3 = 103 mol/m3

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