Experiment No. 8
PREPARATION AND STANDARDIZATION OF NaOH SOLUTION
Materials:
NaOH pellets (AR grade)
Potassium acid phthalate, KHP (AR grade)
Phenolphthalein indicator
Distilled/Deionized water
Procedures
A. Preparation of NaOH Solution
1. Weigh roughly 10.00 g of NaOH pellets (AR grade) in a previously tared
small beaker
2. Add previously boiled and cooled distilled water to dissolve the NaOH
3. Pour the NaOH solution into a 1 L volumetric flask
4. Rinse the beaker with distilled water and pour the rinsing into 1 L
volumetric flask
5. Add enough distilled water to complete the volume to 1 L
6. Store the solution in a 1 L stock bottle with plastic cap
7. Label properly
B. Standardization of NaOH solution using a primary standard:
1. Weigh accurately 1.5 - 2.0 g of KHP (previously dried @ 110 C in an oven for
1 hour) into an Erlenmeyer flask.
2. Dissolve with 50 mL of distilled water by shaking the flask
3. Add 2 drops of phenolphthalein indicator 4. Titrate to a faint pink color
using a base buret
5. Perform 2 determinations.
6. Determine the normality of NaOH solution.
Formulas/Equations:
A. Preparation of Solution
M = g NaOH
MM NaOH x L solution
B. Standardization using a primary standard
MM of KHP = 204.22 g/mole
moles NaOH = moles KHP
MxV
NaOH
= g KHP
MM KHP
M NaOH = g KHP
MM KHP x V
NaOH
Name : Frencess Kaye Simon
Group No: Individual
Year & Section: BSMLS-1A
Date Performed: 03-19-2022
Experiment No. 8
PREPARATION AND STANDARDIZATION OF NaOH SOLUTION
I.
Objectives: (Formulate your own)
1. With a sodium hydroxide solution of around 10.00 g pellets (AR grade),
measure the concentration and determine the solution concentrations.
2. Determine the normality of NaOH solution.
II. Materials (Based on the procedure above)
A. Laboratory Apparatus
1.
Erlenmeyer Flask
2.
Graduated Cylinder
3.
Pipette
4.
5.
6.
Burette
Weighing Bottle
Polyethylene Bottles
B. Chemicals/ Reagents
1. NaOH Pellets
2. Phenolphthalein
3. Standard HCL Solution
III. Data & Results
Trial 1
Trial 2
1.6850
1.6895
Final Reading-NaOH, mL
33.15
33.40
Initial Reading-NaOH
0.00
0.00
Volume NaOH used
0.03315
0.0334
Molarity of NaOH, moles/L
0.2489
0.2477
Wt. of KHP, g
Average Molarity, M
0.2483
Note: Concentrations should be expressed up to the 4th decimal place, for
example 0.1008 M
CALCULATIONS: Refer to the formulas and equations above
Preparation of Solution:
Note: Use the information in your procedure to get the molar concentration of
your NaOH solution
M = g NaOH
MM NaOH x L solution
= 10.00g NaOH
(40.00g/mol) (1L)
= 0.25 mol/L
Standardization of NaOH solution
Trial 1
M NaOH =
g KHP
MM KHP x V NaOH
=
1.6850g
(204.22g/mol)(0.03315L)
= 0.2489 mol/L
Trial 2
M NaOH =
1.6895g
(204.22g/mol)(0.0334L)
= 0.2477 mol/L
Average = 0.2489 + 0.2477
2
= 0.2483 M
IV. ANALYSIS/INTERPRETATION OF RESULTS
• The table's data can be used to calculate the concentration of
solution of sodium hydroxide The amount of NaOH used in the second step
has increased trial. However, as the trials progressed, the molarity of NaOH
(moles/L) declined. Both trials have an average molarity of 0.2483 M.
V.
CONCLUSION
• Standardization is the process of precisely determining a solution's
concentration (molarity). Titration is an analytical process that is
frequently used in standardization. In the course of titration, an exact
volume of HCl is reacted with a known amount of NaOH. The 'end point'
of the titration is identified using an indicator, phenolphthalein, as the
color of the solution changes to light pink. This experiment aims to use
titration under established art to standardize a sodium hydroxide
solution.
VI. REFERENCES
• UIC Lab Manual
• https://www.youtube.com/watch?v=GPn4Urq6ZHw
• https://www.youtube.com/watch?v=VV3CQe10MpI&t=508s
Experiment No. 9
PREPARATION AND STANDARDIZATION OF HCl SOLUTION
Materials
Hydrochloric Acid Standard
NaOH solutiom
phenolphthalein
Preparation of HCl solution:
1. Pour around 50 mL of distilled water into a 1-L volumetric flask
2. Add 21.0 mL of HCl (12 M) cautiously and gradually shaking after addition
3. Mix well, pour HCl solution into a stock bottle (glass is preferred)
4. Label and preserve for future use. {note: solution should be
restandardized prior to use.}
Standardization of HCl solution using a secondary standard:
1. From a Geissler buret (or delivery pipet), run down 20 mL of the
prepared HCl solution into a 250-mL Erlenmeyer flask
2. Add enough distilled water to make the volume to around 50 mL
3. Add 2 drops of phenolphthalein indicator
4. Titrate with prepared NaOH in Expt. 8 using a Mohr buret to a light pink
color end point
5. Perform 2 determinations
6. Determine the molarity of HCl solution
Equation:
HCl + NaOH → NaCl + H2O
moles HCl = moles NaOH mL
HCl x M = mL NaOH x M M
of HCl = mL NaOH x M
mL HCl
Name
:_____________________
Group No. :______________
Year & Section : _________
Date Performed :_________
Experiment No. 9
PREPARATION AND STANDARDIZATION OF HCl SOLUTION
I. Objective/s:
• to make a precise concentration standard solution that can be used to
standardize other solutions
• The exact molarity of a hydrochloric acid solution must be determined.
II. Materials (Based on the procedure above)
A. Laboratory Apparatus
1. Volumetric Flask
2. Stock Bottle (Glass)
3. Geissler buret
4. Erlenmeyer Flask
5. Mohr buret
B. Chemicals/ Reagents
1. Hydrochloric Acid
2. Standard NaOH solution
3. Phenolphthalein
III. Data & Results
Trial 1
Trial 2
Volume HCl used, mL
20.00
20.00
Final Reading-NaOH, mL
19.50
39.10
Initial Reading-NaOH
0.00
19.50
0.0195 L
0.0391 L
Volume NaOH used
Average Molarity of NaOH (from
0.2483M
Expt.8)
Molarity of HCl
0.2438
Average Molarity of HCl
0.4888
0.3663M
Note: Concentrations should be expressed up to the 4th decimal place, for
example 0.1008 M
Calculations :
Trial 1
M of HCl
= mL NaOH x M
mL HCl
= (19.50 mL) (0.25 mol/L)
20.00mL
= 0.2438 mol/L
Trial 2
M of HCl = (39.10 ml) (0.25 mol/L)
20.00 Ml
= 0.4888 mol/L
Average = 0.2438 + 0.4888
2
= 0.3663M
IV. Analysis
• The information in the table can be used to calculate the hydrogen
chloride solution concentration. The amount of HCl utilized has
increased in the second trial. Furthermore, as the trials went, the HCl
Molarity rose. In both trials, the average molarity of hydrogen chloride
was 0.3663 M.
V.
CONCLUSION
• It aims to be exactly the same as experiment laboratory 8, it
standardized, same goes to it distilled water was added first and HCl to
be able to accurately determined the solution concentration.
VI. REFERENCES
• UIC Lab Manual
• https://www.youtube.com/watch?v=lXzAB8woAd8
Experiment No. 10
PREPARATION & STANDARDIZATION OF EDTA SOLUTION
Materials:
Disodium ethylenediaminetetraacetate
Calcium carbonate as primary
standard
Dilute HCl solution
Sodium Hydroxide T.S.
Hydroxynapthol blue powder
Procedures:
A. Preparation of EDTA Solution
1. Dissolve about 4.80 g of EDTA powder in sufficient distilled water in a small
tared beaker
2. Transfer the solution to a 250-mL volumetric flask
3. Rinse the beaker with distilled water, adding the rinsing into the flask
4. Dilute to volume with distilled water
5. Standardize the solution using the following procedure
B. Standardization of EDTA Solution
1. Weigh accurately 100- 150 mg of primary standard CaCO3 and transfer it to a
flask
2. Add 20 mL of distilled water and sufficient diluted HCl to dissolve the
carbonate
3. Dilute with distilled water to 100 mL
4. Add 15 mL of NaOH solution (pH should be around 13), then add a pinch
of
hydroxynapthol blue indicator
5. Titrate the solution with EDTA until it turns into a deep blue color
6. Run a second trial and calculate its molarity
Formula:
Preparation of EDTA solution
M = Disodium EDTA
336.21 g/mole x L solution
Standardization of EDTA solution
mmol EDTA = mmol CaCO3
mL EDTA x M
= wt. of CaCO3
MM of CaCO3
Molarity of EDTA = wt. of CaCO3
100.08 g/mole x L
EDTA
Name
:_____________________
Group No. :______________
Year & Section : _________
Date Performed :_________
Experiment No. 10
PREPARATION & STANDARDIZATION OF EDTA SOLUTION
I. Objective/s:
• Finding out how to Standardize the ETDA solution
• find the molarity of the substance
VI. Materials:
Beaker
Disodium ethylenediaminetetraacetate
volumetric flask
Calcium carbonate as primary standard
burette
Dilute HCl solution Pipette
Sodium Hydroxide T.S
Hydroxynaphthol blue
VI.
Data & Results:
Trial 1
Trial 2
Weight of CaCO3, g
0.1245
0.1312
Final Reading-EDTA ,Ml
25.05
26.20
Initial Reading- EDTA
0.00
0.00
Volume EDTA used,Ml
25.05
26.20
0.0497
0.0500
Molarity of EDTA
Average Molarity
0.0499M
CALCULATIONS:
Preparation:
M=
=
Disodium EDTA
336.21 g/mole x L solution
4.80g EDTA
(336.21 g/mol) (0.25L)
= 0.0571 mol/L
Standardization
Trial 1
Molarity of EDTA =
=
wt. of CaCO3
100.08 g/mole x L
EDTA
0.1245g
(100.08 g/mole) (0.02505L)
= 0.0497 mol/L
Trial 2
Molarity of EDTA =
0.0312g
(100.08g/moll) (0.0262L)
= 0.0500 mol/L
Average = 0.0497 + 0.0500
2
= 0.0499M
IV. ANALYSIS/INTERPRETATION OF RESULTS
• The information in the table can be used to calculate the EDTA solution
concentration. In the second study, the amount of EDTA used (mL) was
increased. Furthermore, as the trials progressed, the molarity of EDTA
increased. In both experiments, the average molarity of EDTA was
0.0499 M.
V.
CONCLUSION
• The principal standard for this experiment was calcium carbonate
(CaCo03), while the indicator was Hydroxynaphthol blue powder. EDTA
is a water-soluble aminopolycarboxylic acid that belongs to the
aminopolycarboxylic acid family. Complexometric titration is used to
achieve this chemical standardization.
VI. REFERENCES
• UIC Lab Manual
• https://www.youtube.com/watch?v=jGb6j4uyjOE
• https://classroom.google.com/c/NDUzMTkyMTU3ODM2/m/MjI4NDI4MDUxNzMw/de
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