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ACID AND BUSINESS PRACTICES A SOLUTION

CHEMICAL PRACTICAL REPORT

ACID AND BASE

A. Purpose of Experiment

Experiment 1

 1. Explain the nature of acid and base solutions with various indicators 

    through experiments.

 2. Estimating the pH of an unknown electrolyte solution based on the 

    bservation of the color change route of various acid and base indicator.

 3. Determine the pH of a solution by using the universal indicator.

Literature review Acids and bases are chemicals that have properties that can

help us distinguish them. A Theory of Arrhenius Acid Bases Since centuries ago,

experts have defined acid and base based on the nature of the solution.

Acidic solutions are acidic and corrosive (damaging metals, marble and other

materials), while alkaline solutions taste somewhat bitter and caustic (slippery,

like soapy). A fairly satisfying concept of acids and bases, and which is still 

accepted today , Put forward by Svante August Arrhenius (1859-1927) in 1884.

AcidAccording to Arrhenius, acid is a compound which, when dissolved into water,

produces H + ions. The properties of acids include:A. Feels sourB. Corrosive 

(damaging metal, marble, and various other materials)C. Ionized 

generates H + ionsD. Has pH <7E. Brighten the blue litmusExamples 

of compounds belonging to acids, namely:¨ HCl¨ H2SO4¨ CH3COOH¨ H3PO4 

Bases

According to Arrhenius, a base is a compound which,

when dissolved into water, produces OH-ions.

 

The basic properties are:

A. Feels bitter

B. It is caustic (slippery like soapy)

C. Ionized generates OH-

D. Has pH> 7

E. Red the red litmus

Examples of compounds belonging to the base, namely:

¨ NaOH

¨ Ba (OH) 2

¨ NH4OH

¨ KOH

 

B. Bronsted Lowry Acid Base Theory

 

According to Bronsted Lowry, acid is a substance that can give protons, while 

bases are substances that can receive proton. So acid = proton donor, 

base = acceptor proton.

This acid-base concept is broader than Arrhenius's acid-base theory because:

1) The concept of Bronsted Lowry acid base is not limited in water solvents, 

but also describes acid-base reactions in other solvents or even solventless 

reactions.

2) Bronsted Lowry acid base can be either a cation or anion. This concept 

can explain the acidic nature of NH4Cl, where the acid carrier 

is NH 4 + which in water can release protons

C. Lewis Acid Base Theory

 

Lewis provides the definition of acid and base based on the handover of electron

pairs, namely:

Acid = acceptor pairs of electrons

Bases = electron pair donors

This concept can explain the acidic acid-base reactions although they do not 

involve the proton of H + ions.

To recognize the properties of a solution can be determined by using acid-base

 indicator. The acid-base indicator is a substance that gives different colors 

to acidic and basic solutions. Given these color differences, acid-base indicators

can be used to find out what a substance includes an acid solution or an alkaline

solution.  

1. Natural Indicators Natural indicators are indicators derived from 

natural materials, such as vegetation. These indicators can be made of herbs, 

flowers, and fruits that must be made in the form of a solution by extracting 

them, then dripping on acid or base solution. Occurs on each indicator is not 

the same. 

2. Artificial Indicators

 One commonly used acid-base indicator is litmus paper, indicator paper uiversal,

and universal indicator solution.Lakmus comes from a moss species of crust that 

can be in the form of a solution or paper. Lakmus is often used in the form of 

paper, because it is more difficult to oxidize and produce a clear color change.  

There are 2 types of litmus paper, namely:- Red litmus paperRed litmus paper turns

blue in alkaline solution and in acidic or neutral solution the color does not 

change (remain red).- Blue litmus paperThe blue litmus paper turns red in acid 

solution and in the base or neutral solution the color remains unchanged 

(remains blue).       The universal indicator paper may change color according 

to the acidity or alkalinity of the substance. Color change occurs when the 

indicator is immersed in an acid or base. 

Commonly used universal indicator solutions are phenolphthalein, methyl orange, 

methyl red and blue bromtimol. If we drip an acid or base solution into 

a universal indicator solution, we can see the color change in the indicator

 solution.In this experiment will be used litmus paper and some other indicators


 to determine the solution and pH value of electrolyte solution A, B, C, and D.


 


  

No

  
          Several categories of indicatorsColor



 

  

Indikator

  

Trayek warna

  

Trayek pH

 

  

1

  
    Lakmus 



  
        Red-Blue



  

5,5-8,0

 

  

2

  

Metil jingga

  
       Red-Yellow



  

3,1-4,4

 

  

3

  

Metilred

  
       Red-Yellow



  

4,4-6,2

 

  

4

  

Bromtimol biru

  

yellow-blue

  

6,0-7,6

 

  

5

  

Fenolftalein

  

not color-red

  

8,3-10,0

 

 

 

A. Tools and Materials

Experiment 1

1. Tools

• Plate drops

•      Measuring cup

• Droppipe

•      Beaker

 

2. Materials

• Electrolyte solutions A, B, C, and D

• Lakmus Paper

• Methyl Orange Indicators

Methyl Orange Indicator

• Red Methyl Indicator

• Phenolphthalein indicator

• Blue timol brom indicator

• Universal indicator



 

Experiment 

A. Alkaline Acid Test

1. Provide drip plates, each filled with sufficient A, B, C, and D 

   electrolyte solutions.

2. Dip the litmus paper in each solution.

3. Observe the color change on litmus paper.

 

B. Determination of pH of the solution using acid-base indicator

 

1. Electrolyte A solution divided into 4 parts then put into the plate drops to 

   taste.

2. Add 3 drops of indicator solution to each column, ie: methyl orange in tube 1,

   methyl red in tube 2, bromtimol blue in tube 3, and phenolphthalein in tube 4.

3. Record your observations on the observation sheet

4. Perform a thorough examination of electrolyte solutions B, C, and D

C. Observation Table Experiment 1A. 


 


  

No

  
  Electrolyte solutioan









  
Test No Solvent









  
Change Solution









 

  

red

  

blue

 

  

1

  

A

  

Blue

  

stay

  

Base

 

  

2

  

B

  

stay

  

red

  

Acid

 

  

3

  

C

  

stay

  

stay

  

Netral

 

  

                                                            4

  

D

  

Blue

  

stay

  

Base

 

  


 
Determination of pH of the solution using acid-base indicator
No Indicator Color of solution after added indicator

  


  


  


  


  


  


 

No	indicator	No Indicator Color  of solution after added  indicator
		A	B	C	D
1	Lakmus red	blue	stay	stay	blue
2	Lakmus blue	stay	red	stay	stay
3	Metil Jingga	jingga	red	jingga	jingga
4	Metil red	yellow	nila	jingga	yellow
5	Bromtimol Biru	biru	jingga	jingga	blue
6	Fenolftalein	nila	not color	not color	nila

 DISCUSSION  

In theory has been mentioned that the acid has a sour taste, while the base has 

a bitter taste. However, it is not recommended to recognize acids and bases by 

tasting them, as many of them can damage the skin (corrosive) or even toxic.

 Acids and bases can be identified using indicator substances, ie substances 

that give different colors in acidic environments and alkaline environments 

(substances whose color may change when interacting or reacting with acidic 

compounds or basic compounds). As in the tests that have been done and obtain 

the following results:Experiment 1A. Alkaline Acid TestIn testing of electrolyte 

A, B, C and D solutions which have been dipped red and blue litmus paper in each 

of these solutions, it can be mentioned that: - In solution A which has been 

dipped in red and blue litmus paper to get red litmus paper change color to blue,

 while blue litmus paper remain, so can be concluded that solution A including 

Basa- In solution B that has been dipped in red and blue litmus paper in obtaining 

red litmus paper remains, while the blue litmus paper becomes red, so it can be 

concluded that solution B including Acid- In solution C which has been dipped in 

red and blue litmus paper in obtaining a fixed red litmus paper, while the blue

 litmus paper remains, so it can be concluded that solution C includes the Neutral 

solution- In solution D which has been dipped in red and blue litmus paper in the 

red litmus paper change color to blue, while blue litmus paper remain, so can be 

concluded that solution D including Bases.B. Determination of pH of the solution 

using acid-base indicatorIn the test of the electrolyte solution A, B, C and D 

each of which the solution has been divided into 4 parts each of which was given 

methyl orange in part 1, methyl red in part 2, methyl bromtimol blue in part 3 

and phenolphthalein in section 4 , It can be mentioned that:Electrolyte A 

solution dipped with:Red litmus paper changes color to blue, blue lacmus 

does not change color, orange methyl orange color change, methyl red turns yellow,

 Bromtimol Blue becomes blue, and Fenolftalein becomes indigo so it can be 

estimated that pH of solution A is 6,2 < A <10 so that solution A can be 

summarized as a base solution.- The electrolyte solution B is dipped with:

 Red litmus paper does not change color, blue litmus turns red, orange methyl 

red color change, methyl red turns into indigo, Bromtimol Blue becomes orange, 

and phenolphthalein becomes colorless so it can be estimated that pH of solution

 B is 3.1 <B <8.3 so that solution B can be summarized as Acid solution. 

Electrolyte solution C which is dipped with:Red litmus paper does not 

change color, blue litmus does not change color, orange methyl orange 

color change, methyl red to orange, Bromtimol Blue becomes orange, and 

Fenolftalein becomes colorless so it can be estimated that pH of solution

 C is = 7 so Solution C can be summarized as a Neutral solutionElectrolyte 

solution D is dipped with:Red litmus paper changes color to blue, blue lacmus

 does not change color, orange methyl orange changes color, methyl red turns 

yellow, Blue Bromtimol becomes blue, and Fenolftalein becomes indigo so it can

 be estimated that the pH of D solution is 6,2 < D <10 so that solution D

 can be summed up as a base solution. 

Alkaline Acid Test-Solution A includes Base-Solution B includes an Acid-Solution 

C including a solution of Netra. -D solution includes alkaline solutionB. 

Determination of pH of the solution using acid-base indicator   - pH of

 solution A is 6.2 <A <10 so that solution A can be summarized as a base 

solution. - pH of solution B is 3.1 <B <8.3 so that solution B can be summarized

 as Acid solution. - pH of solution C is = 7 so that solution C can be summarized 

as Neutral solution. -pH solution D is 6.2 <D <10 so that solution D can be 

summarized as base solution. 

Http://shyraalthafunisa.blogspot.com/2012/05/report-chemicals-about-ph-indikator.

htmlHttp://nyemania.blogspot.com/2014/03/menentukan-ph-satu-larutan.

htmlHttp://bandoqueen.blogspot.com/2012/05/report-kimia-pengujian-ph-data.

htmlSyariffudin.2013.Inti Sari Kimia.Tangerang: Scientific Press. 

Editorial Team K-13.2014.Kimia 2b.Surakarta: Son Nugraha.