Percentage By Mass Of Acetic Acid Biology Essay

Published:

Vinegar is define as "sour wine" or "a sour liquid obtained by acetic fermentation of dilute alcoholic liquids and used as a condiment or preservative." Vinegar is used widely in household and it can serve more than one purpose which generally for food. Vinegar is made by two distinct biological processes, both the result of the action of harmless microorganisms (yeast and "Acetobacter") that turn sugars (carbohydrates) into acetic acid. The first process is called alcoholic fermentation and occurs when yeasts change natural sugars to alcohol under controlled conditions. In the second process, a group of bacteria (called "Acetobacter") converts the alcohol portion to acid. This is the acetic, or acid fermentation, that forms vinegar. Since vinegar can be made from anything with sugar, there are probably too many different types to count made in countries throughout the world.[1]

Rust is define as the red or orange coating that forms on the surface of iron when exposed to air and moisture, consisting chiefly of ferric hydroxide and ferric oxide formed by oxidation. Rust forms due to the reaction of oxygen dissolved in water with iron. Rust also known as corrosion of metal[2].

Lady using a tablet
Lady using a tablet

Professional

Essay Writers

Lady Using Tablet

Get your grade
or your money back

using our Essay Writing Service!

Essay Writing Service

Rust is a generic term to describe different oxides, Fe(OH)2, Fe(OH)3, FeO(OH), Fe2O3.H2O that form when iron corrodes. The common rust that can be found a reddish-brown, Fe2O3.H2O. The oxygen in the air dissolve in water and causes the rust to form. The rust which also known as corrosion is an electrochemical process. That is, it is an electrical circuit where the exchange of electrons (electricity) is conducted by chemical reactions in part of the circuit. These chemical reactions occur at the surface of the metal exposed to the electrolyte. Oxidation reactions (corrosion) occur at the surface of the anode and reduction reactions occur at the surface of the cathode[3].

We could see that rust occurs very easily because the presence of air is almost everywhere and water or wet condition can easily presence anywhere. We could see around ourselves rusting is occur greatly. In the house, in building, in the environment and almost any place. Rusting is not a good thing. It cause metal to appear bad and loss it strength. Rust also dangerous to human because a rusting iron nail can cause health issue if the iron nail struck to human skin. Therefore, we must take precaution about rusting of these iron metal.

The topic that be investigated in this extended essay is to analyse the percentage by mass of acetic acid in different type of vinegar brands and to investigate the potential of vinegar as rust stain remover. The topic caught my interest because there is an article I read about how vinegar is use to neutralize an acidic ground so that plant could grows but when they use different vinegar on the ground, it gives out different result on the plant growth. So, I come out with conclusion that different vinegar has different amount of acid concentration which in this case , it is an acetic acid.

I know that acid could be use to remove rust stain. Vinegar is acidic because of the presence of acetic acid. Therefore, it questions me whether could vinegar remove rust stain? Therefore, I can relate my first experimental with the second experimental. The chosen area of study is rusting since my experiment focus more on rusting. Therefore, the research was narrowed down to a specific question to study.

Does different vinegar has different concentration of acetic acid and how significant if there really a difference?

Does vinegar could be use as rust stain remover as it is acidic due to presence of acetic acid?

2. Methodology for data collection

2.1. Methdology for neutralisation process

To find the concentration of acetic acid in different types of vinegar brands,a neutralisation process follow the standard procedure is carries out. First , the apparatus is set up . The burette is clamped on the retort stand. Then, 2.0 ml of vinegar is measured using measuring cylinder. The 2.0 ml vinegar which is Earth Brand is insert in conical flask. After that, 48.0 ml of distilled water is measuring using measuring cylinder. Then, the distilled water is mixed with the vinegar in the conical flask. This procedure has to be carried out because vinegar is very concentrated so dilution process has to be done.

Lady using a tablet
Lady using a tablet

Comprehensive

Writing Services

Lady Using Tablet

Plagiarism-free
Always on Time

Marked to Standard

Order Now

After mixed, the initial weight of vinegar with conical flask is measure using weighing balance. This procedure has to be carried out to find the mass of 2.0 ml of vinegar assumed that different vinegars has different density. Then , sodium hydroxide is inserted in the burette about 50.0 ml. The conical flask is placed under the burette. 3 drops of phenolphathalein is added into the dilute vinegar.

The neutralisation process is started as soon the alkali is added into the conical flask. The conical flask is swirled gently. When the mixture in conical flask has slightly change in colour which from colourless to pink, the alkali is added slowly because it is a sign that neutralisation process almost complete. The end of titration is indicated when the mixture remains in pink colour. The titration process is stopped .

The volume of sodium hydroxide needed to neutralise 2.0 ml of vinegar is recorded and final weight of vinegar with conical flask is weighed. The difference between final and initial reading is calculated to find the mass of 2.0 ml of vinegar. All the data is recorded in the table. The experiment is repeated using different type of vinegar which is Yeo's and Jalen.

Table of list of apparatus and materials

Burette, ±0.05 cm3

Beaker, ±0.5

Retort stand and clamp

Phenolphathalein

Sodium hydroxide

Different vinegar brands (Jalen, Yeo's, Earth Brand)

Conical flask ,±0.5

pipette

Weighing balance , ±0.0001

Rod

Distilled water

2.2 Metadology for rusting process and rust stain removal

This experimental procedure is carried out because it is hard to determine the degree of rusting of any random metal. Therefore, I fixed the type of metal use which is iron nail and the time left for iron to rust which is approximately I day (24 hours) .

The materials is ready which is iron nails, magnesium ribbon, vinegars and apparatus which is digital stopwatch. The initial mass of iron nail is weighed and the data is recorded. Then, the magnesium ribbon is rubbed with sand paper to remove any stain on the magnesium ribbon, to clean the magnesium ribbon. Rusting is very slow process. Therefore, magnesium ribbon is use because it will speed up the rate of rusting or iron.

After the magnesium ribbon is cleaned, the magnesium ribbon is folded around the iron nail. Then , a mineral bottle is cut to get the bottom part of mineral bottle and form a cup like. Then, the cup is filled with tap water.. The iron nail with magnesium is consistently dipped in the water and left to be exposed to air. The procedure follow about one day of experiment. After one day , the iron nail is take out and magnesium ribbon is remove from it. The iron nail which already rust now Is weigh again to get mass of rust formed on the iron nail. All the data of the experiment is recorded in a table. The experiment is repeated about 8 times because we have there different types of vinegar and each needed to be test individually.

The process to remove rust stain is carried out. A bottom of mineral bottle is cut and amount of vinegar is insert into the cup. The rust iron nail then placed into the cup. The reaction is observed. The time taken for the iron rust to remove completely from the iron nail is recorded. The data and result is tabulated.

Table of list of apparatus and materials

Burette, ±0.05 cm3

Beaker, ±0.5

Magnesium ribbon

Bottle cup

Sand paper

Different vinegar brands (Jalen, Yeo's, Earth Brand)

Conical flask ,±0.5

Measuring cylinder, ±0.05

Weighing balance , ±0.0001

Iron nail

Distilled water

Table of variable and method of controlling variable

Variable type

Variable

Method of controlling

Indepenent

Concentration of acid (different type of vinegar brands) (dm3/mol)

By using vinegar of different brands for the experiment.

Dependent

Rate of rust stain removal

By measuring time taken for the rust stain to be completely remove then the rate of rust remove is calculate by using formula

(mass/ time)

Controlled

Lady using a tablet
Lady using a tablet

This Essay is

a Student's Work

Lady Using Tablet

This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.

Examples of our work

Type if metal use

Iron nail is use throughout the experiment

temperature

The experiment is conducted in same room

Time for iron to rust

Fixed the time for the iron to rust which is I day or 24 hours

Mass of magnesium ribbon

Fixed the mass of magnesium ribbon use

3. Data collection and processing

3.1 Data collection and processing for experiment 1

Type of vinegar brand

Volume of NaOH needed to neutralize acid in vinager (ml)

Trial 1

Trial 2

Trial 3

Earth Brand

42.80

44.20

39.60

Yeo's

29.40

27.20

29.00

Jalen

38.60

43.80

42.40

Quantitative data

Type of vinegar brand

Initial weight of 2.00 ml of vinegar with conical flask (g)

final weight of 2.00 ml of vinegar with conical flask (g)

Weight of vinegar in 2.00 ml of vinegar(g)

Earth Brand

52.38

54.66

2.28

Yeo's

52.51

54.55

2.04

Jalen

52.71

54.61

2.06

Qualitative date

The initial colour of vinegar and alkali is colourless. When, both substance is mixed the colour still remain in colourless. But when the mixture undergo titration process, when the end point of titration reach, the colour of mixture turns form colourless to pink.

Equation= CH3COOH (aq) + NaOH (aq) → NaCH3COO (aq) + H2O (l)

1.Earth Brand

Calculate number of moles for NaOH

= MV

1000

(32.20 ml of NaOH solution added x 1.0 molar of NaOH)

1000

= 0.0322 moles of NaOH

If look at equation , you will see that the acetic acid in vinegar reacts with sodium

hydroxide in a 1:1 ratio. This means that the number of moles of NaOH will be the same as the

moles of acetic acid, which means that the number of moles of acetic acid in the 2.00 mL of

vinegar is also 0.0322 moles.

Calculate the amount of acetic acid in Earth Brand.

molar mass for acetic acid = 60 g/mol

therefore, amount of acetic acid is number of mole x molar mass of acetic acid

0.0322 moles x 60 g/mol = 1.932 g of acetic acid

To calculate the percentage by mass of acetic acid in vinegar (Earth Brand):

Volume of vinegar use= 2.28 g

mass of acetic acid in vinegar = 1.932 g

(1.932/2.28 ) x 100 = 84.74 %

To calculate concentration of acetic acid in vinegar (Earth Brand)

m = n / v

m= Molarity

n= Number of moles of acetic acid

v = volume of vinegar use

M= ( 0.0322 / 2.00 )

= 0.0161

2.Yeo's

Calculate number of moles for NaOH

= MV

1000

(28.53 ml of NaOH solution added x 1.0 molar of NaOH)

1000

= 0.02853 moles of NaOH

If look at equation , you will see that the acetic acid in vinegar reacts with sodium

hydroxide in a 1:1 ratio. This means that the number of moles of NaOH will be the same as the

moles of acetic acid, which means that the number of moles of acetic acid in the 2.00 mL of

vinegar is also 0.02853 moles.

Calculate the amount of acetic acid in Yeo's.

molar mass for acetic acid = 60 g/mol

therefore, amount of acetic acid is number of mole x molar mass of acetic acid

0.02853 moles x 60 g/mol = 1.712 g of acetic acid

To calculate the percentage by mass of acetic acid in vinegar (Yeo's):

Volume of vinegar use= 2.04 g

mass of acetic acid in vinegar = 1.712 g

(1.712/2.04 ) x 100 = 83.92 %

To calculate concentration of acetic acid in vinegar (yeo's)

m = n / v

m= Molarity

n= Number of moles of acetic acid

v = volume of vinegar use

M= ( 0.02853 / 2.00 )

= 0.01427

3. Jalen

Calculate number of moles for NaOH

= MV

1000

(31.60 ml of NaOH solution added x 1.0 molar of NaOH)

1000

= 0.03160 moles of NaOH

If look at equation , you will see that the acetic acid in vinegar reacts with sodium

hydroxide in a 1:1 ratio. This means that the number of moles of NaOH will be the same as the

moles of acetic acid, which means that the number of moles of acetic acid in the 2.00 mL of

vinegar is also 0.03160 moles.

Calculate the amount of acetic acid in Jalen.

molar mass for acetic acid = 60 g/mol

therefore, amount of acetic acid is number of mole x molar mass of acetic acid

0.03160 moles x 60 g/mol = 1.896 g of acetic acid

To calculate the percentage by mass of acetic acid in vinegar (Jalen):

Volume of vinegar use= 2.06 g

mass of acetic acid in vinegar = 1.896 g

(1.896 /2.06) x 100 = 92.04 %

To calculate concentration of acetic acid in vinegar (Jalen)

m = n / v

m= Molarity

n= Number of moles of acetic acid

v = volume of vinegar use

M= ( 0.03160 / 2.00 )

= 0.0158

Type of vinegar

Percentage by mass of acetic acid in vinegar (2.00 ml of vinegar) (%)

Concentration of acetic acid in vinegar (%)

Earth brand

84.74

0.01610

Yeo's

83.92

0.01427

Jalen

92.04

0.01580

Discussion

The volume for vinegar use need to be weighed to find the mass of vinegar. From the result, it shows that different vinegars has different density so different vinegars will have different mass of 2.00 volume used.

Based on the result , it shows that different type of vinegar brands has different concentration of acetic acid but the number differ only by little amount. Therefore the effect of different acids on the rate of rust stain removal should not show significant difference between type of vinegars.

3.2 Data collection and processing for experiment 2

Quantitative data

Earth Brand

Type of metal

Trial

Initial weigh of iron nail before rusting process(g)

Final weigh of iron nail after rusting process (g)

Mass of rust produce on iron nail (g)

Time taken for rust stain on iron nail to be remove by vinegar (s)

Iron nail

1

4.3271

4.7281

0.401

103

2

4.3233

4.7453

0.422

117

3

4.3233

4.7503

0.427

125

Average time taken for the rust stain to be remove by vinegar

115.00

Type of metal

Trial

Initial weigh of iron nail before rusting process(g)

Weight of iron nail after rust stain is remove by vinegar (g)

Amount of iron form the rust (g)

Iron nail

1

4.3271

4.1997

0.1274

2

4.3233

2.9843

0.1339

3

4.3233

4.1731

0.1502

Yeo's

Type of metal

Trial

Initial weigh of iron nail before rusting process(g)

Final weigh of iron nail after rusting process (g)

Mass of rust produce on iron nail (g)

Time taken for rust stain on iron nail to be remove by vinegar (s)

Iron nail

1

4.3267

4.7797

0.453

153

2

4.3248

4.7228

0.398

109

3

4.3253

4.7673

0.442

133

Average time taken for the rust stain to be remove by vinegar

131.67

Type of metal

Trial

Initial weigh of iron nail before rusting process(g)

Weight of iron nail after rust stain is remove by vinegar (g)

Amount of iron form the rust (g)

Iron nail

1

4.3267

4.1932

0.1335

2

4.3248

4.1872

0.1376

3

4.3253

4.1821

0.1432

Jalen

Type of metal

Trial

Initial weigh of iron nail before rusting process(g)

Final weigh of iron nail after rusting process (g)

Mass of rust produce on iron nail (g)

Time taken for rust stain on iron nail to be remove by vinegar (s)

Iron nail

1

4.3241

4.7521

0.428

131

2

4.3213

4.7393

0.418

116

3

4.3280

4.7480

0.420

121

Average time taken for the rust stain to be remove by vinegar

122.67

Type of metal

Trial

Initial weigh of iron nail before rusting process(g)

Weight of iron nail after rust stain is remove by vinegar (g)

Amount of iron form the rust (g)

Iron nail

1

4.3241

4.1767

0.1474

2

4.3213

4.1852

0.1361

3

4.3280

4.1883

0.1397

Quantitative data

The iron nail is silver in colour , Magnesium ribbon is silver in colour, the tap water is colourless and the vinegar is colourless.

When the iron nail coiled with magnesium ribbon in water, effervescence occurs around magnesium ribbon and bubbles formed around iron nail.

After several hours, reddish brown rust started to form around the iron nail and continue to form through time.

During rust removal, the iron nail is insert in vinegar and bubbles seems to formed around the rust.

After several times the rust remove from the iron itself and dissolve in acid.

Discussion

Rusting is the corrosion of iron and readily occurs in the alloy steel. The formation of a reddish brown flakes which loosely adheres to the iron is called rust.

Based on the experiment it shows that vinegar could serve as one of the substance that can remove rust stain on metal. It also clearly shows that different vinegar has different degree of removing the rust stain because due to different concentration of acid but not significantly differ from each other.

After rusting the nail weighs more. Rust forms when iron metal is oxidized by oxygen in the presence of water. Rust is known as iron oxide. Iron oxide as a molecule consist of iron with oxygen and water. Basicly, the rust form is originally mass from the iron but the mass of oxygen comes from the atmosphere. When the rust form on the iron nail, the mass of iron rust increased by the mass of oxygen that combined with the iron.

In the presence of oxygen and water,

Reduction half equation: 4e- + 2H2O(l) + O2(g) --> 4OH-(aq)

The nail easily oxidised at the tip or the head part of iron nail. The crystal lattice of iron is distorted and the iron atoms will be easily oxidised.

Oxidation half equation: 2Fe(s) --> 2Fe2+(aq) + 4e-

Therefore the overall net equation is

2Fe(s) + 2H2O(l) + O2(g) --> 2Fe2+(aq) + 4OH-(aq)

In addition of, the Fe2+ and OH- ions will move and diffuse through the water. When both ions meet they will react to produce precipitate , iron (II) hydroxide , Fe(OH)2 .

These iron (II) hydroxide will be further oxidise to iron (II) hyrdroxide, Fe(OH)3 and then dehydrated to produce rust.

Chemical eqution for rusting process :

2Fe(s) + 2H2O(l) + O2(g) --> 2Fe2+(aq) + 4OH-(aq)

Fe2+(aq) + 2OH-(aq) --> Fe(OH)2(s)

Fe(OH)2(s) + O2 --> Fe(OH)3(s)

Fe(OH)3(s) - dehydrates --> Fe2O3.nH2O(s) or rust

The chemical formula for rust is Fe2O3.nH2O(s)

5. Acetic acid is presence in vinegar. Vinegar works well than other acid because it less

attack the iron nail itself. When the iron with rust is soaked into the acid, it will

dissolve and loosen the crumbly hydrated iron oxide to form a soluble salt, in these

case it will be iron acetate. They can also replace it with a thin film of smooth hard

oxide on the surface of the iron to help it resist further hydrated oxidation.

Equation of reaction between acetic acid and rust:

3CH3COOH + FeO(OH) --> Fe(CH3COO)3 + 2H2O

and iron (III) acetate Fe(CH3COO)3 is water soluble.

6. Acid dissolve rust but also promote rusting. The surface will be clean after the the

rust is remove but it will easily rust even after the acid is washed away. To prevent

this, the iron nail must be soaked in hot water and dry it.

7. Dissimilar metals rust faster than single metals because of electrochemical

reactions, so example steel rusts faster than iron, and joints between dissimilar

metals rust very quickly.Similarly in this experiment, magnesium will promote

rusting of iron.

4. Processed result

Earth brand

Type of metal

Trial

Percentage by mass of acetic acid in vinegar (2.00 ml of vinegar) (%)

Concentration of acetic acid in vinegar (%)

Mass of rust produce on iron nail (g)

Time taken for rust stain on iron nail to be remove by vinegar (s)

Rate of rust stain remover

(g/s)

Iron nail

1

84.74

0.01610

0.401

103

0.0039

2

0.422

117

0.0036

3

0.427

125

0.0034

Average rate of rust stain remove

0.0036

Yeo's

Type of metal

Trial

Percentage by mass of acetic acid in vinegar (2.00 ml of vinegar) (%)

Concentration of acetic acid in vinegar (%)

Mass of rust produce on iron nail (g)

Time taken for rust stain on iron nail to be remove by vinegar (s)

Rate of rust stain remover

Iron nail

1

83.92

0.01427

0.453

153

0.0029

2

0.398

109

0.0036

3

0.442

133

0.0033

Average rate of rust stain remove

0.0033

Jalen

Type of metal

Trial

Percentage by mass of acetic acid in vinegar (2.00 ml of vinegar) (%)

Concentration of acetic acid in vinegar (%)

Mass of rust produce on iron nail (g)

Time taken for rust stain on iron nail to be remove by vinegar (s)

Rate of rust stain remover

Iron nail

1

92.04

0.01580

0.428

131

0.0033

2

0.418

116

0.0036

3

0.420

121

0.0035

Average rate of rust stain remove

0.0035

5. Conclusion

The first thing this research show that each vinegar has it own concentration of acetic acid. Eventhough the volume used for the experiment 1 is 2 cm3, but it does not mean of the more acetic acid available in vinegar the higher the concentration of acetic acid in vinegar because different vinegar has different density. These also effect the concentration of acetic acid in vinegar. From the experiment and calculation, it shows that the concentration of acid for vinegar brands of Earth Brand, yeo's and Jalen accordingly is 0.01610 mol/dm3, 0.01427 mol/dm3 and 0.01580 mol/dm3.

The concentration of acetic is what cause the difference in the vinegar taste. To high amount of acetic acid will cause the vinegar to taste bad. The experiment also shows that there is not much significant difference of acetic acid concentration between different type of vinegar brands. The vinegars use is the product of Malaysia . Different result may show if I test of the products of other country. For Malaysia products, there is very low concentration of acetic acid in vinegars. Because of it low acidic properties , it could be use in many ways.

These second thing research also shows that vinegar could serve a potentially rust stain remover but in low degree because it has low acid concentration. Still, it could be use safely because the acidic concentration is not harmful and vinegar is easy to obtain rather than any other applications. From the result obtain, it shows that the higher the concentration of acid, the higher the rate of rate of rust removal. Eventhough the concentration is not significantly different from each other, but it does show different rate of rust removal.

From the calculation, the rate of rust removal for Erath brand, yeo's and Jalen accordingly is 0.0036 gs-1, 0.0033 gs-1, and 0.0035 gs-1. Therefore I could say that , Earth Brand is a better rust stain remover than Yeo's and Jalen , but Jalen is better than Yeo's. Therefore, vinegar is a potentially rust stain remover . But vinegar could only remove rust stain that only form only on surface of metal . It cannot remove the rust that has been deeper into metal . Higher acid concentration is needed to remove the rust. Overall, different vinegar has different percentage by mass of acetic acid and vinegar is a highly potential rust stain remover.