INORGANIC AND ORGANIC CHEMISTRY LABORATORY REPORT Subject Lecturer Instructor Faculty/Class Date of Experiment Date of Lab. Report Semester Time of Experiment
: Inorganic and Organic Chemistry Laboratory : Dr. rer. nat. Filiana Santoso, Mr. Hery Susanto M.Si : Mr. Tabligh Permana, Mr.Hery Sutanto M.Si, Ms. Sylvia Yusri, S.Si : Life Science/LS 2A : 6 May 2014 : 20 May 2014 : 2 : 14.00 17.00 p.m
Experiment:
Name:
Campus BSD City Bumi Serpong Damai Tangerang 15321 – Indonesia
–
Conductivity Measurement
Kristania Hadhiwaluyo Chita Sakina Putrianti Elias Harmanto
Tel. Fax.
+62 21 537 6221 +62 21 537 6201
[email protected] www.sgu.ac.id
I.
Objectives
To measure the conductivity of solution.
To study the factors affecting the conductivity of a solution.
II.
Theoretical Background
Salinity and conductivity measure the water’s ability to conduct electricity, which provides a measure of what is dissolved in water. Basically, c onductivity measures the water’s ability to conduct electricity and it is the opposite of resistance. Pure, distilled water is a poor conductor of electricity as there are only a very small amount of ions present inside it. When salts and other inorganic chemicals dissolve in water, they break into tiny, electrically charged particles called ions. Ions increase the water’s ability to conduct electricity. Common ions in water that conduct
electrical current include sodium, chloride, calcium, and magnesium. Salinity and conductivity are related with one another because dissolved salts and other inorganic chemicals conduct electrical current, conductivity increases as salinity increases.
This experiment will measure the conductivity of two different solution, Potassium Chloride (KCl(aq)) and Copper Nitrate (Cu(NO3)2.3H20(aq)). Conductivity is typically measured in aqueous solutions of electrolytes. Electrolytes are substances containing ions, i.e. solutions of ionic salts or of compounds that ionize in solution. The ions formed in solution are responsible for carrying the electric current. Electrolytes include acids, bases and salts and can be either strong or weak. Most conductive solutions measured are aqueous solutions, as water has the capability of stabilizing the ions formed by a process called solvation, which is a process by which solvent molecules surround and interact with solute ions or molecules.
The electrolytes itself can be divided into two kinds of electrolytes, strong and weak. Strong electrolytes are substances that are fully ionized in solution and inside the solution more ions are present. As a result, the concentration of ions in solution is proportional to the concentration of the electrolyte added. They include ionic solids and strong acids, for example HCl. Solutions of strong electrolytes conduct electricity because the positive and negative ions can migrate largely independently under the influence of an electric field. Whereas, the weak electrolytes are substances that are not fully ionized in solution. For example, acetic acid partially dissociates into acetate ions and hydrogen ions, so that an acetic acid solution contains both molecules and ions. A solution of a weak electrolyte can conduct electricity, but usually not as well as a strong electrolyte which contain more number of ions.
Actually, there are many other factors that can affect the conductivity of a solution besides the concentration of ions, and the type of solution (whether it is a strong or weak electrolyte), which is the temperature. However, in this report only the effect of concentration of ions and the type of solution will be discussed.
III.
Equipment and Materials
Equipment:
- Volumetric Flask, 100 cm3, 2 -
Beaker glass, 100 cm3, 5
- Volumetric Pipette, 25 cm3, 2
IV.
-
Dropping pipette
-
Bulb, 2
-
Digital Balance
-
Petri dish, 2
-
Spatula, 2
-
Funnel
-
Glass rod
-
Conductivity meter
Materials:
-
H2O(l), distilled water
-
Potassium Chloride (KCl(s))
-
Copper Nitrate (Cu(NO3)2.3H20(s))
Procedures
1. Preparation of Parent Solutions a. Potassium Chloride – 0.1 M KCl(aq) 1) The mass needed to make 0.1 M KCl(aq) solution was calculated as follows
( ) ⁄ 2) 0.75 g of KCl was taken from its container using a spatula and measured using the digital balance 3) 0.75 g of KCl was placed inside a petri dish where a little amount of distilled water (H20) was mixed together using a glass rod
4) A funnel was attached to a 100 cm3 volumetric flask 5) 0.75 g of KCl in the petri dish was poured into the 100 cm3 volumetric flask 6) Distilled water (H20) was poured until it reaches the meniscus of the 100 cm3 volumetric flask 7) The 100 cm3 volumetric flask containing the 0.1 M KCl(aq) solution was poured into the 100 cm3 glass beaker. b. Copper Nitrate – 0.1 M Cu(NO3)2.3H20(aq) 1) The mass needed to make 0.1 M Cu(NO3)2.3H20(aq) solution was calculated as follows
( ) ( )
( ) ( ) ⁄ 2) 2.416 g of Cu(NO3)2.3H20 was taken from its container using a spatula and measured using the digital balance 3) 2.416 g of Cu(NO3)2.3H20 was placed inside a petri dish where a little amount of distilled water (H20) was mixed together using a glass rod 4) A funnel was attached to a 100 cm3 volumetric flask 5) 2.416 g of Cu(NO3)2.3H20 in the petri dish was poured into the 100 cm3 volumetric flask 6) Distilled water (H20) was poured until it reaches the meniscus of the 100 cm3 volumetric flask 7) The 100 cm3 volumetric flask containing the 0.1 M Cu(NO3)2.3H20(aq) solution was poured into the 100 cm3 glass beaker.
2. Dilution of Parent Solutions a. Dillution of 0.1 M KCl(aq) 1) 0.01M 10ml of 0.1M of KCl solution was taken using the 25 cm3 volumetric pipette into the 100 cm3 glass beaker and added with 90ml H2O 2) 0.005M
50ml
of 0.01M of KCl solution was taken using the 25
cm3 volumetric pipette into the 100 cm3 glass beaker and added with 50ml H2O
3) 0.001M
20ml
of 0.005M of KCl solution was taken using the 25
cm3 volumetric pipette into the 100 cm3 glass beaker and added with 80ml H2O 4) 0.0005M
50ml
of 0.0005M of KCl solution was taken using the
25 cm3 volumetric pipette into the 100 cm3 glass beaker and added with 50ml H2O 5) 0.0001M
20ml
of 0.0005M of KCl solution was taken using the
25 cm3 volumetric pipette into the 100 cm3 glass beaker and added with 80ml H2O b. Dillution of 0.1 M Cu(NO3)2.3H20(aq) 1) 0.01M
10ml
of 0.1M of Cu(NO 3)2.3H20 solution was taken using
the 25 cm3 volumetric pipette into the 100 cm3 glass beaker and added with 90ml H2O 2) 0.005M
50ml of 0.01M of Cu(NO3)2.3H20 solution was taken
using the 25 cm3 volumetric pipette into the 100 cm3 glass beaker and added with 50ml H2O 3) 0.001M
20ml
of 0.005M of Cu(NO3)2.3H20 solution was taken
using the 25 cm3 volumetric pipette into the 100 cm3 glass beaker and added with 80ml H2O 4) 0.0005M
50ml
of 0.0005M of Cu(NO 3)2.3H20 solution was taken
using the 25 cm3 volumetric pipette into the 100 cm3 glass beaker and added with 50ml H2O 5) 0.0001M
20ml
of 0.0005M of Cu(NO3)2.3H20 solution was taken
using the 25 cm3 volumetric pipette into the 100 cm3 glass beaker and added with 80ml H2O
3. Conductivity Measurement 1) The conductivity meter was put into the beaker containing the 0.1 M Cu(NO3)2.3H20(aq) solution and the result was read and recorded in the data table as shown below Concentration
Conductivity ( s) Potassium Chloride - KCl(s)
Copper Nitrate - Cu(NO3)2.3H20(s)
0.01
Over reading limit
Over reading limit
0.005
447
596
0.001
89
164
0.0005
34
65
0.0001
10
19
SAMPLE
78
665
2) The 2nd step was repeated for the other beaker containing Cu(NO3)2.3H20(aq) with different concentration including the provided unknown sample but before the conductivity meter was used it was rinsed with distilled water 3) Another conductivity meter was put into the beaker containing the 0.1 M KCl(aq) solution and the result was read and recorded in the data table as shown below 4) The 2nd step was repeated for the other beaker containing KCl(aq) with different concentration including the provided unknown sample but before the conductivity meter was used it was rinsed with distilled water
V.
Observation (Data)
Concentration
Conductivity ( s) Potassium Chloride - KCl(s)
Copper Nitrate - Cu(NO3)2.3H20(s)
0.01
Over reading limit
Over reading limit
0.005
447
596
0.001
89
164
0.0005
34
65
0.0001
10
19
SAMPLE
78
665
VI.
Discussion
Graph of Concentration vs Conductivity 600
596
y = 117638x
500 ) s
447
y = 89834x
( 400 y t i v i t 300 c u d n200 o C
100
Conductivity KCl(s) 164
65 34
10 0 0
19
Conductivity Cu(NO3)2.3H20(s) Linear (Conductivity KCl(s))
89
0.001
0.002
0.003
0.004
0.005
0.006
Linear (Conductivity Cu(NO3)2.3H20(s))
Concentration (M)
Concentration of Potassium Chloride Sample - KCl(s)
M %error of Concentration of Potassium Chloride Sample - KCl(s)
| | | | 13.2%
Concentration of Copper Nitrate Sample - Cu(NO 3)2.3H20(s)
M %error of Concentration of Copper Nitrate Sample - Cu(NO 3)2.3H20(s)
| | | | 13%
ANALYSIS Basically, conductivity measures the water’s ability to conduct electricity and it is the opposite of resistance. When salts and other inorganic chemicals dissolve in water, they break into tiny, electrically charged particles called ions, which increase the water’s ability to conduct electricity. Common ions in water that conduct electrical current include sodium, chloride, calcium, and magnesium. However, the ability of different substance conducting electricity is different from one another due to some factors, they are the concentration of ions, the type of solution (whether it is strong or weak electrolyte, knowing the fact that conductivity is commonly measured in electrolytes), and temperature.
In this experiment, concentration is the only factor that used to determine the conductivity of the two different solution, Potassium Chloride (KCl (aq)) and Copper Nitrate (Cu(NO3)2.3H20(aq)). From the results present in the data table and the graph of concentration vs. conductivity, it is proven that the conductivity increased as the concentration increased. The word concentration would mean the amount of a substance or in these case ions in a specific space or substance. If the concentration is high, that means the ions dissolved in the solution are in a big amounts. Since the ions formed in solution are responsible for carrying the electric current, the more ions that are present inside that solution would mean the higher the capability of the solution to conduct electricity.
However, it is also seen from both of the results present in the data table and the graph that even though the concentration of these two different solution, Potassium Chloride (KCl(aq)) and Copper Nitrate (Cu(NO3)2.3H20(aq)) are the same and their conductivity increases, still the overall conductivity of Copper Nitrate (Cu(NO3)2.3H20(aq)) solution is still higher than the Potassium Chloride (KCl(aq)) solution. This is due to the fact that Potassium Chloride (KCl(aq)) only has two ions, whereas the Copper Nitrate (Cu(NO 3)2.3H20(aq)) has more ions composing the structure of the substance, therfefore it is inevitable that Copper Nitrate (Cu(NO3)2.3H20(aq)) wwhich contain more amount of ion will have a higher overall conductivity value than the Potassium Chloride (KCl(aq)) solution.
VII.
Conclusion
Primarily, conductivity measure the water’s ability to conduct electricity, which provides a measure of what is dissolved in water. Conductivity is typically measured in aqueous
solutions of electrolytes, which are substances containing ions, i.e. solutions of ionic salts or of compounds that ionize in solution. Although there are some factors that may affect the conductivity of a certain substance, the main factor, which is also the one observed in this experiment would be the number of ions present or dissolve inside the solution, in this case the Potassium Chloride (KCl (aq)) and Copper Nitrate (Cu(NO3)2.3H20(aq)) solution. Based on the result of our experiment, as the number of ions composing the overall structure of that certain substance increases, the higher conductivity value that the substance will has. Furthermore, the higher concentration of the solution would also mean the higher capability of the substance to conduct electricity. It is due to the fact that a higher concentration would mean the more amounts of ions that are present inside the solution. Since ions are the one which are responsible to conduct electricity, more ions would mean more electricity that is conducted.
VIII.
References
Sutanto, Hery, and TablighPermana. Inorganic and Organic Chemistry 1 Laboratory Manual .Tangerang: Swiss German University, 2013. Print. "Conductivity Theory and Practice." Laboratory of Analytical Chemistry . University of Crete, n.d. Web. 17 May 2014. . "Definition of Solvation." Definition of solvation . N.p., n.d. Web. 16 May 2014. . "Electrolytes, ionisation and conductivity." Everything Science . N.p., n.d. Web. 16 May 2014. . "What is Conductivity?." Environmental Monitor . N.p., n.d. Web. 16 May 2014. . "What is the scientific definition of concentration?." - Ask.com . N.p., n.d. Web. 16 May 2014. .
