using english to report

PH SCALES AND USE INDICATORS

Day :Monday

Date: March 27, 2017

 Aim    :

1. Make larytan standard acid and base in various concentration.

2. Measure PH solution with various indicators.

3. Selects indicators corresponding to PH.

4. Measure PH solution by using PH meter.

Benefits:

1. After conducting this experiment we know how to make acid and bassa standard solutions in various concentrations.

2. Through this practicum we can measure the pH of the solution using various indicators.

3. With this practicum can choose the appropriate indicator

4. Makes us better understand how to measure the solution ph by using pH meter

Practice Questions

1. Phenolatelin is one of the prevalent indicators. How is the color in acid solution? In alkaline solution?

2. What is PH? How much is a neutral solution?

3. If 0.01 mol of HCl is present in 10 liters of solution, what is the concentration of H + and how much is PH?

4. How is the relationship between [H +] and [-OH] in aqueous solution, if [H +] = 10-4

Answer

1. Acid solution: colorless

Alkaline solution: pink

2. PH is a number of provisions which express the strength of acidity or wetness of a solution. PH neutral = 7

3. M HCl = mol = 0.01 = 10-3 M

               V (L) 10         

[H +] = a x ma

        = 1 x 10-3

= 10-3

PH = -Log [H +]

      = -Log 10-3

      = 3

4. The relationship [H +] with [-OH] is forming H2O by reaction of H + + - OH, H2O with PH = 7

KW = [H +] [- OH]

10-4 = [10-9] [- OH]

[-OH] = 10-10

1. Theoretical Basis

The concept of acids and bases is based on several properties which are represented by a group of compounds in the solution in water. Based on the properties shown, acid is a compound that has a sour taste, and redacts blue lacmus. Basaadalah compounds that have a bitter taste, and red litmus menduh. In aqueous solutions, acids produce H + and alkaline produce OH-. The H + ions of the acid and the OH- ions of the base may react to H2O so that the solution is neutral. (Epinur 2011)

Ionization Pure water only ionizes 0.001%. Ionization can be seen in the equation of the reaction:

H2O + H2O ↔ H3O + + OH-

The hydronium ion, H3O +, is often written H +, so the ionization of water is: H2O ↔ H + + OH-

From the pure water reaction equation we see a number of H + ions and OH-ions, called H + ion concentrations and OH ion concentrations, commonly written with [H +] and [OH-]. Based on experiments at the temperature of 250C pure water obtained [H +] = [OH -] = 1x10-7 mol / L. (Bird 1985)

In an acidic atmosphere [H +]> 10-7 mol / L, so [H +]> [OH-].In an alkaline atmosphere there is the opposite state, [OH -]> [H +]. Water dissociation can be viewed as an equilibrium reaction so that it can be written

H2O ↔ H + + OH-

The constant of water supply, Kw is obtained by multiplying [H +] by [OH-] to obtain the equation:

Kw = [H +] [OH-] = [1x10-7] 2 = 1x10-14 (sukardjo 1990)

At room temperature of 250C multiplication [H +] [OH-] always 1x10-14.

The primacy or basicity of a solution depends on which ion stands out in solution, if [OH +] = [H +] then the solution is neutral, [OH -]> [H +] solution is basic and [H +]> [OH-] acidic solution , If:

[H +] = 10-3 mol / L

From the equation for equilibrium the water is obtained:

Kw = [H +] [OH-] = 1.10-14

10-3 x [OH-] = 10-14

Thus, [OH-] = 10-11 mol / L

PH Scale Based on the meaning of [H +] and [OH-] we can know the pH scale .. pH is negative logarithm [H +] or mathematically written: pH = -log [H +]

Example:

[H +] = 10-3 mol / L

PH = 3

If known [OH-] = 10-2 mol / L

Thus, [H +] = 10-12

PH = 12 (petrucci 1987)

2. Tools and materials

Tools:

ü   Reaction Tubes

ü  Mixer Rod

ü  Pipette Drops

Material :

ü  HCl 0.01 M

ü  Flute Water

ü  Boiling Water

ü  NaOH 0.01 M

ü  Methyl Meth

ü  Fenolfatelin

ü  Bromtimol Bureau

ü  Yellow Alizarin

ü  Red Methyl

ü  Cake Soda

ü  Vinegar Solution

ü  Fruit Juice

ü  carbonated drink

ü  Shampoo

ü  Liquid Detergent

ü  Ammonia

ü  Aspirin Tablets

3. Working procedures

A. Acidic area, pH 2 to 6

1. Fill the first tube with a 0.01 M HCl standard solution because the HCl is perfectly ionized then the pH of this solution is 2.

2. Make another solution with pH 3,4,5, and 6 with each dilution 10 times, starting with pH 2. The trick is as follows:

3. To make pH 3, take 1 mL pH 2 solution, dilute it with boiled distilled water.

4. Pipette 1 mL of a solution of pH 3, dilute with 9 mL boiling water to obtain a PH 4 solution, in the same way prepare a solution of pH 5 and 6

B. Area of ​​neutral pH, pH 7

Use boiled water, feed into the test tube.

C. base region, pH 6 to pH 12

1. Fill the first tube with a 0.01 M NaOH solution which will produce a solution with a pH of 12.

2. Dilute 1 mL of a 1 tube solution with 9 mL of distilled water of distilled water to make a solution of pH 11, stirring the solution.

3. Make a solution of pH 10, 9, 8, in the same way as in section A.

4. Store about 1 mL of any solution made to parts A, B, and C to be used in the experimental test tube.

5. Label each tube according to its pH, then place it on the reaction tube shelf.

6. Drop one drop of indicator on each test tube until color change occurs. Observe and note the indicator color change on each pH and note also where the color change occurs.

D. The pH indicator of various Substances

Using the indicator provided determine the pH of the following substances:

A. Vinegar solution (dilute 10 x)

B. Orange juice

C. Carbonated beverage (dilute 50%)

D. Shampoo

E. Liquid detergent (5% solution)

F. Ammonia for domestic use

G. Baking soda (10%)

H. The aspirin tablet (salicylic acid is dissolved in 20 mL water)

1. Pipette about 2 mL of each solution of the above substance and insert each into 5 test tubes.

2. Tetskan 2 drops indicator that has been provided into each maasing the test tube.

3. Compare the color with standard solution.

4. Determine the pH of each solution based on the color of the solution after the addition of the indicator.

E. Determination of pH by using pH meter

1. Demonstration of pH meter use is done by assistant.

2. Before use pH meter should be calibrated

3. Electrode dipped into standard solution made. Record the pH meter reading of some of the standard solutions selected.

4. Observational data

Standard pH measurement results	Standard pH	Kind of indicator
		Alizarin	Methyl orange	blue Methyl	Red Methyl	PP
HCl	2	Clear	Red	Blue	Pink	Clear
HCl	3	Pink muda	Pink	Blue	Pink	Clear
HCl	4	Clear	Pink	Blue	Pink	Clear
HCl	5	Clear	Pink	Blue	Pink	Clear
HCl	6	Clear	yellow	yellow	Pink	Clear
NaOH	7	Pink	yellow	yellow	Pink	Clear
NaOH	8	purple	yellow	yellow	Pink	Pink
NaOH	9	purple	yellow	yellow	Pink	Pink
NaOH	10	purple	yellow	yellow	Pink	Pink
NaOH	11	Pink faded	yellow	yellow	Pink	Pink
NaOH	12	Pink pudar	yellow	yellow	Pink	Pink

matter	Indicator		pH	Information
	Universal	pp		Acid
Vinegar	Changed		3	Acid
Floridina	Changed		4	Acid
Buavita	Changed		4	Acid
Sprite	Changed		4	Acid
Fanta	Changed		4	Acid
Cocacola	Changed		3	Acid
Thresemme		It does not change color	<8,3	Base
Rejoice		It does not change color	<8,3	Base
Clear		It does not change color	<8,3	Base
Dove		It does not change color	<8,3	Base
Lifeboy		It does not change color	<8,3	Base
Deterjen		Little changed	8,3-10	Base
Wipol		Change color	>10	Base
Baking soda		It does not change color	<8,3	Acid
aspirin	Changed		3	Acid

5. Discussion

·         Indicator of phenolphthalein

This experiment was conducted to find out how big the actual pH of the ingredients used in materials in daily life. This indicator undergoes a colorless red-color change at an interval pH of 8.3-10. This means that pH below 8.3 if this indicator ditetesi there will be no change in color. While the pH above 10 will result in a change of color. Based on the results of experiments that have been done terhatal shampoo consisting of thresemme, rejoice, dove, clear and lifeboy terya have the same pH interval that is <8.3. The solution using the pp inductor in this experiment was detergent. Detergent is often used dalm keehidupan day day do we know as one of base solution. When tested using a pp indicator obtained data that the detergent pH is between 8.3-10 due to slight changes in color. The next solution is ammonia, a commonly used ammonia is wipol. From the experiment it turns out pH wipol> 10 is marked with a change of color when the pp indicator drop. The last solution using pp indicator is baking soda, after examined the pH of baking soda is <8.3. The disadvantage of this indicator is not being able to determine the pH value of a solution for sure.

·         Universal indicator

The universal indicator is a mixture of various indicators that can show the pH of a solution of the color change. Universal Indicator consists of 2 kinds of litmus paper and indicator of solution. In this experiment used is a litmus paper indicator equipped with a color map showing how many ph is actually from a solution. The results of this experiment gave 2 different pHs of all the materials tested. The first is a solution that actually has ph 3 ie vinegar solution, cocacola, and aspirin solution, vinegar solution is usually used to add flavor to food, cocacola is a beverage while aspirin is a medicine. Three of these solutions are said to have a pH of 3 based on the color change on the universal indicator that has been adjusted to the color map.

The second pH obtained is 4 fluorine, buavita, sprite, and Fanta. This solution is claimed to have the same acidity after being tested using universal indicator paper and color changes adjusted to the color map. Based on this we know that drinks are widely consumed by the community both in the form of citrus juice and carbonated drinks are classified as acid because it has a pH of 3-4.

Discussion

In this experiment the results obtained largely match the theory. Kesalaha in this experiment due to lack of practicable praktikan in conducting trials. According to the literature that has been read and several other research results about the pH on the materials used in daily life are as follows:

A. PP Indicator

Route ph 8.3-10 clear color for vinegar, purple color ph 8 sahmpo purple ph 9, rinso purple ph 10, clear sprite ph 4, pulpy orange nodes ph 2, clear aspirin ph 4, soda pink ph 7.

B. Indicator methyl orange

Route ph 3.1-4,4 red-orange-yellow color. For pink vinegar ph 3, yellow shampoo ph 11, yellow rinso ph 12, yellow sprite ph 5.pulpy orange yellow ph 2, aspirin ph 8, baking soda yellow ph 4.

C. Red methyl indicator.

Route ph 4.4-6.2 red-yellow color. For red vinegar ph 3, yellow shampoo ph 4, yellow rinso ph5, sprite red ph 3.pulpy orange yellow ph 4, aspirin ph 6, baking soda yellow ph 5.

D. Indicator

Route ph 10-12 warnakuning-red. For clear vinegar ph 3, clear shampoo ph 5, clear rinso ph 8, clear sprite ph 5.pulpy orange clear ph, clear aspirin ph 7, clear baking soda ph 6.

E. Blue bromtimol indicator

Route ph 6-7,6 yellow-blue color. For yellow vinegar ph 3, yellow shampoo ph 4, rinso blue ph 5, yellow sprite ph 3.pulpy orange yellow ph 4, aspirin ph 6, baking soda blue ph 5.

6. Post-practice questions

1. Why is baking soda solution acidic? Explain!

2. After you have done the experiment, group the substances in experiment D into groups of acid, neutral and base substances!

Answer the question

1. Because the pH of baking soda is 7. Sodium soda is sodium hydrogen carbonate, sodium bicarbonate, and bicarbonate of soda larrutan in water is weak acidic and based on baking soda literature can redden the blue litmus.

2. Acid: vinegar, carbonated beverages, orange juice, baking soda.

Base: shampoo, detergent, aspirin.

Neutral : -

7. Conclusion

From the experimental results, it can be concluded that:

1. In making the solution can use dilution formula

M1V1 = M2V2

2. Ph solution can be measured using indicator and ph-meter

3. The solution can be divided into 3

·         Acid solution of ph <7

·         base ph solution> 7

·         Neutral solution ph = 7

4. A pH meter consists of an electrode (measuring probe) connected to an electronic device that measures and displays pH.

8. Bibliography

1.      Bird.tony.1985.Kimia Fisika.Jakarta:Gramedia

2.      Epinur,dkk.2011.Penuntun pratikum.Jambi:Unja

3.      petrucci,Relph.1987.Kimia Dasar.Bogor :Erlangga

4.      Sukardjo.1997.Kimia Dasar 1. Jakarts:PT. Rinrka Cipta