İhsan Doğramacı Foundation
Bilkent Erzurum Laboratory School
2011-2012 Academic Year
Spring Semester
Chemistry Lab Report-2
Titration
08.04.2012
Kemal Vatansever
9-D 216
LAB REPORT – 2
Purpose:
We did two Lab activities. The purpose of the first lab activity is about understanding
which matter is base or acid with use an indicator. In the second first lab, we expected to
familiarize the Titration equipments and understand what titration is.
Hypothesis:
In first lab activity, we used litmus paper to understand which
matter is base or acid; hence we expected that when we put the indicator
(litmus paper) on the solution or a substance, like a lemon, litmus paper
color changes with the conditions of blue or red. After we did it we
measure the strength (acid or base strength) of the substances or
solutions. In the second experiment we expected to familiarize the
equipments of titration and to understand what the uses of the
equipments are and to understand what titration is.
Equipments:
In the First Lab Activity:

Litmus Paper

Bi Carbonate of Soda

A paper to measure the

Lemon and its vinegar
strength of the substance

Apple and its vinegar
Apple, Lemon, Grape

Vinegar
vinegars.

Water


Carbonate

NaOH

Sodium Carbonate

Sulphuric acid

HCl

𝑁𝐻3
In the Second Lab Activity:

Burette

Glass Flask

Measuring cylinder

A beaker

Methyl Orange

Funnel
Procedure:
Lab Activity – 1:
C – 1: Lemon  pH = 2
C – 2: Apple  pH = 4
C – 3: Vinegar  pH = 1-2
C – 4: Lemon Vinegar pH = 1-5
C – 5: Apple Vinegar  pH = 3
C – 6: Water + Carbonate  pH = 8
C – 7: Water + Carbonate + Apple Vinegar
 pH = 7
C – 8: Sodium carbonate  pH = 10
C – 10: 𝐻𝐶𝑙  pH = 1
C – 11: 𝑁𝑎𝑂𝐻  pH = 14
C – 12: 𝐻2 𝑆𝑂4  pH = 1
C – 13: 𝑁𝐻3  pH = 12
Lab Activity – 2:
What is Titration?
A titration is a technique where a solution of known concentration is used to determine the
concentration of an unknown solution.
C – 1:
Find the concentration of a solution of hydrochloric acid, using a 1 M solution of
sodium carbonate as your standard solution.
First step:
Calculate the number of moles of sodium carbonate used.
1000 𝑐𝑚3 = 1 mole
25
25 𝑐𝑚3 = 1000 𝑥1  0.025 mole
Second Step:
By the equation, find the molar ratio of acid to alkali.
2HCl(𝑎𝑞) + Na2 CO3 (𝑎𝑞) → 2NaCl(𝑎𝑞) + H2 O(𝑙) + CO2 (𝑔)
2 moles
1 mole
2 moles of acid 1 mole of alkali.
Third Step:
Work out the number of moles of acid neutralized.
Ratio= 1 : 2
Fourth Step:
0.025 moles of alkali, 2 x 0.025 moles of acid.  0.05 acid.
Calculate the concentration of the acid.7
𝑐𝑜𝑛𝑐𝑒𝑛𝑡𝑟𝑎𝑡𝑖𝑜𝑛 =
𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑚𝑜𝑙𝑒𝑠
𝑣𝑜𝑙𝑢𝑚𝑒 𝑖𝑛 𝑑𝑚3
0.05
=0.0278 = 1.8 𝑚𝑜𝑙/𝑑𝑚3 Concentration of HCl: 1.8M
C – 2:
25 𝑐𝑚3 of vinegar were neutralized by 20 𝑐𝑚3 of 1 M sodium hydroxide solution.
What is the concentration of ethanoic acid in the vinegar?
Step – 1: Calculate the number of moles of sodium hydroxide used.
20
1000
𝑥1 = 0.02 mole
Step – 2: From the equation, find the molar ratio of acid to alkali.
CH3 COOH(𝑎𝑞) + NaOH(𝑎𝑞) → CH3 COOHNa(𝑎𝑞) + H2 O(𝑙)
1 moles
1 mole
So the ratio is 1 : 1
Step – 3: Number of moles of acid:
Ratio = 1 : 1  0.02 mole alkali, 0,002 mole of acid.
Step – 4: Calculation
𝑐𝑜𝑛𝑐𝑒𝑛𝑡𝑟𝑎𝑡𝑖𝑜𝑛 =
𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑚𝑜𝑙𝑒𝑠
0.02
=
= 0.8 𝑚𝑜𝑙/𝑑𝑚3
𝑣𝑜𝑙𝑢𝑚𝑒 𝑖𝑛 𝑑𝑚3
0.025
So the concentration of ethanoic acid in the vinegar is 0.8 M
C – 3:
10 𝑐𝑚3 of a liquid cleaner were neutralized by 12 𝑐𝑚3 of 2 M sulphuric acid. What is
the concentration of ammonia in the cleaner?
Step – 1: Calculate the number of moles of acid neutralized.
12
1000
𝑥2 = 0.0024 moles
Step – 2: From the equation, find the molar ratio of acid to alkali.
H2 SO4 (𝑎𝑞) + 2NH3 (𝑎𝑞) → (NH4 )2 SO4 (𝑎𝑞)
Ratio is 1 mole of acid to 2 moles of alkali.
Step – 3:
Ratio = 1 : 2
0.0024 mole of acid
0.0048 mole of alkali.
Step – 4: Calculation
𝑐𝑜𝑛𝑐𝑒𝑛𝑡𝑟𝑎𝑡𝑖𝑜𝑛 =
𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑚𝑜𝑙𝑒𝑠 0.0048
=
= 0.48 𝑚𝑜𝑙/𝑑𝑚3
𝑣𝑜𝑙𝑢𝑚𝑒 𝑖𝑛 𝑑𝑚3
0.01
So the concentration of ammonia in the cleaner is 0.48 M
The uses of the Equipments in Titration:
Burette: We understand how it works and we practiced on the tab. We open that tab
and we closed, when the solution in the glass flask become colourless.
Glass Flask: We put acid or base with methyl orange.
Measuring cylinder: We measured the solutions volume
A beaker: We use to spill the water to the Glass Flask
Methyl Orange: We use to change the calour of the solution which is in the glass
flask.
Funnel: We use to spill the water to the Burette clearly and easily.
Results:
In the First Lab Activity: We used the indicator (Litmus Paper) to understand whether
is acid or base. After that we measured the strengths of the substances and solutions. We
decided that if the acids’ strength is near to the degree of pH 1, it is a strong acid. Like that,
we decided that if the bases’ strength is near to the degree of pH 14, it is a strong acid.
In the Second Lab Activity: We familiarize the equipments of the titration. We
learned the equipments’ purposes and names. With that we could clearly understand what
we use on the titration experiment. Finally we understand that, what titration is. We use
titration to find the value concentration to unknown solution with using a solution which we
know its concentration.
Conclusion:
In the lab activity 1 we observed the results and the pH strength of the substances
and we used litmus paper.
In the lab activity 2 we understand clearly what titration is and we solve some
problems and we identify the equipments of titration.
In the two activities we reached the results of our hypothesis.