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chemical practicum report
Acid and base titration


CHAPTER I
preliminary
1.1 Background
Titration is a method to determine the content of a substance by using another substance that has been determined by its concentration. Titrations are usually distinguished by the type of reaction involved in the titration process, for example when the acid-base reaction involves the so-called acid-base titration, the redox titration for the titration involving the oxidation reduction reaction, the titration of the complexometry for the titration involving the formation of a complex reaction and so forth. (Here only discussed about acid-base titration).
Substances to be determined are referred to as "titrant" and are usually placed in the Erlenmeyer, whereas the known substances are referred to as "titers" and are usually placed in a "burette". Both titer and titrant are usually solvents.
The acid-base titration is also called alkalimetric addition titration. The acid base concentration or concentration can be determined by volumetric method with acid-base titration technique. Volumetry is a quantitative chemical analysis technique for determining the sample rate by measuring the volume of the solution involved in the reaction based on chemical equivalence. Chemical equality is fixed through the known titration endpoint of the indicator color change and the sample rate to be determined by calculation based on the reaction equation.
Acid base titration is a technique for determining the concentration of acidic or basic solutions. The reaction that occurs is an acid-base reaction (neutralization). The known solution of cosentration is called the standard solution. The equivalent point is the point when the right acid and base just react with the indicator color change. The end point of the titration is the occurrence of the indicator color change.
1.2 Experiment Objectives
Our aim is to practice this:
1. Students are able to apply titration techniques to analyze that example
Contains acid.
2. Students are able to menstandari solution.
CHAPTER II
Literature review
            Standardization can be done by titration. Titration is the process of determining the concentration of a solution by reacting a predetermined concentration solution (standard solution). Acid base titration is a titration by using acid-base reaction (neutralizing reaction). The analytical procedure for this acid-base titration is by volumetric titration, ie measuring the volume of an acid or base that reacts (Syukri, 1999).
When the indicator color changes, the titration is stopped. The indicator changes color at the point equivalent. Pasda acid base titration, known as the equivalence point and end point of titration. The equivalent point is the point on the titration process when the acid and base are exactly reacting. To know the equivalent point used indicator used. When a color change occurs, it is called the end point of the titration (Sukmariah, 1990).
The process of determining the concentration of a solution ascertained is appropriately known as standardization. A standard solution can sometimes be prepared by using a desirable, precisely weighted sample of solutes, in a properly measured solution volume. Sufficient substances in this regard are few, called the primary standard (Sukmariah, 1990).
Substances used for primary standard solutions, must meet the following requirements:
1. Easily obtained in pure form and in known circumstance
s Its purity.
2. Must be stable.
3.This is easily dried, not hygroscopic, so it does not absorb water vapor,
Not absorbing CO2 at the time of weighing (Sukmariah, 1990).
Solutions having known molar concentrations, can easily be used for reactions involving quantitative procedures. The quantity of solute in a volume of the solution, in which the volume is carefully measured, can be accurately determined from the following basic relations:
   Mol = liter x molar concentration
                 or:
   Mmol = ml x molar concentration
The stoichiometric calculations involving the molar are known to be even simpler. With the equivalent weight division, two solutions will react appropriately to each other when both contain the same equivalent grams. In this connection, both normality must be expressed in the same unit, as well as both volumes (Brady, 1990).
Known chemical analyzes of the samples are qualitative analysis and quantitative analysis. Qualitative analysis provides information about what components of the compiler in a sample, while quantitative analysis provides information about some of the many compositions of a component in the sample. In other words, qualitative analysis is concerned with the number or amount of compounds in the sample. The most commonly applied conventional quantitative analysis is titrimetric analysis. The titrimetric analysis is carried out by concentrating a particular sample with a standard solution, ie a known solution of concentration. The calculation is based on the required titrant volume until the titration equivalent point is reached. The titrimetric analysis based on the occurrence of acid-base reactions between samples with standard solutions is called alkalimetric acid analysis. If the standard solution used is an acidic solution then the analysis carried out is the analysis of acidimetry. Conversely, if a base is used as a standard solution, the analysis is referred to as an alkalimetric analysis. The concentration of acid-base solution often uses units of kemolaran (M), then the formula can be changed. Conversion from a dolphin to normality is multiplying the valence (n) of acid or base by the polarity. Instead of a normality to units of kemolaran is dividing kemolaran with the valence of acid or base. This conversion can be formulated as follows:
By the formula:
VA. MA. NA = VB. MB. NB
Information :
VA = Volume before dilution
MA = Molarity before dilution
VB = Volume after dilution
MB = Molarity after dilution
NA = Validity of acid
NB = Validity of base (Keenan, 1991).
The term titrametric analysis refers to quantitative chemical analysis carried out by determining the volume of a solution whose concentration is known appropriately, which is required to react quantitatively with the solution of the substance to be determined. The solution with known strength (concentration) is called a standard solution. The weight of the substance to be determined, calculated from the standard volume used and the known laws of stoichiometry. Formerly used the volumetric analysis, but now it has been replaced with titrimetry analisiss, because the latter is considered better declared the titration process, while the former can be confused with volume measurements, such as those involving gases. Reagents with known concentrations are called titrants, and the substance being titrated is called titrat (Khopkar, 1990).
A reaction may be used as a basis for titrimetric analysis if it meets the following requirements:
1. The reaction must take place quickly, so the titration can be done in a time
Not too long.
2. The reaction must be simple and known with certainty, so that equality is obtained
Which is definitely in the reactant.
3. The reaction must take place perfectly.
4. Having a large equivalent mass (Sukmariah, 1990).
For titrimetric analysis it is easier if we understand the equivalent system (normal solution) because at the end point of titration the equivalent amount of the titrated agent = the sum of the equivalent of the titrant agent. The equivalent weight of a substance is very difficult to make definitions, depending on the kind of reaction. Volumetry can be divided into:
1. Asidi and alkalimetry
2. Oxidimetry
3. Argentometry
Acidimetry is a known acid concentration, whereas alkalimetry when known is its basic concentration. Acid base titration is five. Four of them are:
1. Titration of acid with a strong base
At the end of the titration salts will form from strong acids and strong bases.
     Example:
               HCl + NaOH NaCl + H2O
2. Titration of weak acid and strong base
At the end of the titration salts are formed which are derived from weak acids and strong bases. Ex:
    Acetic acid with NaOH.
               CH3COOH + NaOH CH3COONa + H2O
3. Titration of weak base and strong acid
At the end of the titration salts will form derived from weak bases and strong acids.
     Eg: NH4Cl and HCl
               NH4OH + HCl NH4Cl + H2O
4. Titration of weak acids and weak bases
At the end of the titration salts will form derived from weak acids and weak bases.
     For example: acetic acid and NH4OH
               CH3COOH + NH4OH CH3COONH4 + H2O (Sukmariah, 1990).
Increased levels of heavy metals in seawater will be followed by elevated levels of heavy metals in marine biota which in turn through the food chain will lead to acute and chronic poisoning, even carcinogenic in marine consumer (Keman, 1998). The research that has been done by Think (1993) with Atomic Absorption Spectroscopy (SSA) method concluded that shell from Kenjeran Suraba Beach contains Cadmium (Cd) weight of 1.22 ppm and shellfish from Keputih Beach Surabaya, containing 1, 09 ppm Cadmium heavy metal. Another study conducted by the same method by Moesriati (1995) on several species of fish and shellfish at Kenjeran Beach Surabaya stated that the heavy metal content of Cadmium in clam meat was 1.21 ppm (Sukmariah, 1990).
CHAPTER III
Methodology

3.1 Tools and Materials
             1. 0.1 M NaOH
             2. HCl 0.1 M
             3. H2C2O4
             4. Penolphetalin indicators
             5. Erlenmeyer
             6. Buret 50 mL
             7. Statif and clamps
             8. Measuring glass 25 mL or 10 mL
             9. The glass funnel

3.2 How it Works
· Standardization of 0.1 M NaOH solution
Ways of working :
1. Wash 3 erlenmeyer, pipette 10 mL 0.1 M oxalic acid solution and insert it into
In each erlenmeyer and add it into each erlenmeyer 3 Drops of the penolphtalein (PP) indicator.
2. Flow the NaOH solution present in the burette bit by bit until it is formed
Pink color that does not disappear when the glass erlenmeyer shaken.
3. Record the volume of NaOH used.
4. Repeat the same way for erlenmeyer II and III.
5. Calculate molarity (M) NaOH.

· Determination of HCl concentrations
1. Wash 3 erlenmeyer, pipette 10 Ml of 0.1 M HCl solution and put in each
Erlenmeyer.
2. Add into each erlenmeyer 3 drops of phenolphtalein indicator
(PP).
3. Flow the NaOH solution present in the burette bit by bit until it is formed
Pink color that does not disappear when the glass erlenmeyer shaken.
4. Record the volume of NaOH used.
5. Repeat the same way for erlenmeyer II and III.
6. Calculate molarity (M) HCl.

CHAPTER IV
Observation result
Standardize NaOH with oxanic solution
No
Procedure
Repeated
Averages
I
II
III
1
Volume of 0.1 M oxalic acid solution
10 ml
10 ml
10 ml
10 ml
2
The volume of NaOH is used
20 ml
19,8 ml
19,7 ml
19,8 ml
3
Molarity (M) NaOH
0,05 M
0,05 M
0,05 M
0,05 M


Standardize HCl with HCl solution
No
Procedure
Repeated
Averages
I
II
III
1
Volume of HCl solution
10 ml
10 ml
10 ml
1o ml
2
The volume of NaOH is used
25 ml
25 ml
12 ml
20,6 ml
3
Molarity (M) NaOH
Based on the above experimental results
0.05 ml
4
Molarity (M) HCl solution
0,04 ml
0,04 ml
0,08 ml
0,05 ml

CHAPTER V
Discussion
Factors that affect the occurrence of errors are:
1. Buret leak.
2. Error during weighing HCl.
3. Vision errors during vollume measurement on the burette.
4. Error observing the color change.

· Standardization of NaOH with oxalic acid solution.
The reaction that occurs between NaOH and oxalic acid is as follows:
 
2NaOH + H2C2O4 Na2C2O4 + 2H2O
In the standardization of NaOH to oxalic acid the indicator used is penolftalein or PP 1%, when the indicator is added the color of the solution remains clear, after titrated with 20 mL NaOH the solution turns into pink or pink. Likewise so. The color change in the solution is caused by the resonance of the electron isomer. Various indicators have different ionization constants, thus showing the colors in different pH ranges. Penolftalein indicator is an indicator made by condensation of phthaline anhydride with phenol.
            
From the results of lab work, get NaOH morality through the calculation as follows:
NaOH morality in experiment I:
             V1.M1 = V2.M2
      
             10.0,1 = 20.M2
        
                  
     = M2                          
               0.05 = M2
                          

NaOH morality in experiment II:
V1.M1 = V2.M2
10.0,1
 = 19,8.M2
            = M2
    0.05 = M2
Molarity of NaOH in experiment III:
   
         V1.M1 = V2.M2
             10.0,1 = 19,7.M2
                  
      = M2
               0.05 = M2
The average morality of NaOH aadalah as follows:
0.05 M + 0.05 M + 0.05 M =
0,05 M
So the NaOH content in the titration process is 0.05 M.

Standardize NaOH with HCl solution
The reaction that occurs between NaOH and HCl is as follows:
  NaOH + HCl NaCl + H2O
In the standardization of NaOH to HCl indicator used is penolftalein or PP 1%, when the indicator is added the color of the solution remains clear, after titrated with 20 ml of NaOH the solution turned into pink or pink. Likewise so. The color change in the solution is caused by the resonance of the electron isomer. Various indicators have different ionization constants, thus showing the colors in different pH ranges. Indicator penolftalein is an indicator made by condensation of fthalein anhydride with phenol. The solutions formed when NaOH and HCl are mixed are salt and water.
             From the results of the lab, in obtaining Morality HCl through the calculation as follows:
HCl morality in experiment I:                                      HCl morality in experiment I
             V1.M1 = V2.M2
                                                   V1.M1 = V2.M2
              10.0,1 = 25.M2
                                                     10.0,1 = 12.M2
                    = M2
                                                                 = M2
                 0.04 = M2
                                                                 0.08 = M2
Moralitas HCl pada percobaan II :
            V1.M1=V2.M2
             10.0,1=25.M2
                   = M2
                0,04=M2
Jadi Moralitas rata-rata HCl aadalah sebagai berikut:
0,04 M + 0,04M + 0,08 M     =  0,053 M
Jadi kadar HCl pada proses titrasi yang dilakukan adalah sebanyak 0,053 M .

CHAPTER VI
Cover
6.1 Conclusions
The conclusions I can take from the lab that we do are:
1. To find out the acid solution can be determined by use
A basic base solution already known, and preferably a base solution Can be determined by using a known acid solution Measure.
2. On standardization of NaOH solution to oxalic acid and NaOH to HCl
Indicator used is penolphtalein or PP 1% as much as 3 drops, Thus it is found that the molarity of NaOH used is 0.05 M And HCl molarity of 0.05 M.

BIBLIOGRAPHY

Brady, J. E. 1990. Chemistry University: Principles and Structure Binding 1. Erland, Jakarta.
Keenan, Charles W. et al. 1991. Chemistry For Universities. Jakarta, Erland.
Khopkar, S. M. 1990. Basic Concepts of Analytical Chemistry. University of Indonesia, Jakarta.
Sukmariah. 1990. Chemical Medicine Edition 2. Binarupa Aksara, Jakarta.
Shukri. 1999. Basic Chemistry 2. Bandung, ITB.

 

Komentar

  1. Explain the requirements of a substance that can be used as an acid-base indicator!

    BalasHapus
    Balasan
    1. The requirements of a substance can be used as an indicator that is to have a different color when put into an acid or base solution

      Hapus
  2. Does all acid base titration use indicator?

    BalasHapus
    Balasan
    1. Titration is a quantitative method of analysis to determine the content of a solution. In the titration of the substance to be determined its concentration is titrated by a solution whose concentration is known appropriately and accompanied by the addition of an indicator. The known solution of concentration is called standard solution or tandar solution, while the indicator is a substance that gives a sign of change when the titration ends is known as the end point of titration. Based on the definition of titration, acid-base titration is a method of determining the level of acid solution with peniter Titrant) an alkaline solution or the determination of an alkaline solution with a titrant of an acid solution, with the general reaction occurring; Acid + Basa -> Salt + Water. This neutralizing reaction occurs in the titration process. The titration end point is the condition at which the color change of the indicator occurs. The end point of the titration is expected to approach the titration equivalent point, ie the condition at which the acid solution reacts precisely with the base solution.

      Hapus
  3. Hi, if we mix a solution from one solution with another solution then the color will change, my question here is what causes the color change?

    BalasHapus
    Balasan
    1. In the titration process, we must be familiar with the mixing technique between acid and base. In titration when we use a standard acid or acid titrant solution, it is referred to as acidimetric titration. And when using standard base or basic titrant solutions, it is referred to as alkalimetric titration. To identify and identify a compound belonging to an acid or base group, one of the ways used is to give a little indicator to the solution. If in a solution given with pp indicator then the solution is pink, then the solution is alkaline. And if the solution is indicated pp then the solution is colorless (clear), then the solution is acidic.

      Hapus
  4. Hi dina , please explain to me tips for make a report of experiment , the steps to make it or something , thanks

    BalasHapus
    Balasan
    1. 1) Title of experiment; Write down the title of the experiment. Beginning with the capital letters at the beginning of each word, in the middle of the line.
      2) The purpose of the experiment; Write down the purpose of the experiment. There are goals, all written.
      3) The study of theory; Write down the theoretical basis underlying the experiment, searching for learning resources or books or accesing on the internet. The theory obtained by stacking logically, hierarchically, in accordance with the demands of science. After reviewing the theory, then arrange the hypothesis based on the results of the theory study and adjust it to the purpose of the experiment. The hypothesis is a temporary answer to the experiment to be performed.
      4) Tools and materials; Write down the correct tools used at the time of the experiment. The correct material used written is written according to what was used during the experiment.
      5) Procedures / ways of working; Convey how to work with active sentences instead of sentences. Do not imitate the operational word that exists on the LKS, which is a sentence. Make the sentence tell the active sentence so as to tell what has been done during the experiment.
      6) Observation result; Write down the observations according to what was obtained during the experiment. Data can be written descriptively or in tabular form of observation result. Make the best observation while doing the experiment, so that obtained data accurate and reliable.
      7) Data analysis and discussion; In doing data analysis requires critical thinking, apply the theory that has been written by combining the observation results. The results are discussed descriptively or calculated (if any), by applying the existing concepts by using theories and reviews of the various angles of the birth. Each of the results obtained is discussed in detail to get the right conclusions.
      8) Conclusions and suggestions; Write conclusions concisely according to the purpose of the experiment. What do you want to achieve during the experiment, write the conclusions. The conclusion is the jawan of the proposed hypothesis.
      9) References; Write the library (book) that you have read as a source of reading or learning. The writing of the bibliography follows the guidelines already given; Namely author name, year of publication, book title, publisher city, publisher. If accessed from the internet, write down when it is accessed.

      Hapus
  5. Determine the concentration of H + ions present in 250 mL of 0.15 M HCN solution if Ka HCN = 5 x 10-10

    BalasHapus
    Balasan
    1. HCN ------> H⁺ + CN⁻
      [HCN] = M = 0,15 M
      V = 250 ml
      Ka = 5 x 10⁻¹⁰
      [H⁺]² = Ka.M
      = 5 x 10⁻¹⁰ x 0,15
      = 75 x 10⁻¹²
      [H⁺] = 8,7 x 10⁻⁶

      Hapus

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