Zheena Marie F. Paler
BSChE-3
I. Briefly discuss the following:
1. Differentiate soap and detergent.
Soap is made from fat or oil, water, and an alkali or basic salt. It has been around since 2800
B.C. It can be used to wash our hands, bodies, and, of course, laundry. Laundry detergents,
as opposed to soap, include more synthetic chemicals. The key difference is that detergents
contain man-made sulfates, which clean clothes, hair, hands, and dishes when they come
into contact with water. Another distinction between soap and detergent is how they behave
in water. The formation of scum in hard water, which is difficult to clean and is known to change
laundry into a color, is a significant disadvantage of washing with soap. Detergents, on the
other hand, react less to minerals in water and hence do not leave this residue. Another
distinction is that soap is known for being environmentally friendly, whereas detergent is not.
This is because soaps are entirely biodegradable and are obtained from natural sources such
as vegetable oils and animal fats. Detergent, on the other hand, contains a branched
hydrocarbon chain that is non-biodegradable and synthetically generated, and these
compounds can form a thick foam that kills aquatic life.
2. How does soap and detergent exerts cleaning action?
Soap's cleansing activity is determined by its polar and non-polar structures, as well as the
application of solubility principles. Of course, the lengthy hydrocarbon chain is non-polar and
hydrophobic (repelled by water). The soap molecule's "salt" end is ionic and hydrophilic (water
soluble). The surfactant nature of such compounds facilitates their usage as cleaning agents
by lowering the surface tension of water, allowing it to penetrate and moisten a range of
substrates. When soap is dissolved in water, the ionic-salt end of the molecule is drawn to it.
Water repels the non-polar hydrocarbon end of the soap molecule. The soap molecules "stand
up" on the surface because the polar carboxyl salt end is attracted to the polar water. The
water repels the non-polar hydrocarbon tails, causing them to appear to stand up.
3. What is a surfactant? What are the different types of surfactants?
Surfactants are a key ingredient in cleaning detergents. The term surfactant refers to a
surface-active agent. Surfactants, as the name implies, stimulate activity on the surface being
cleaned in order to trap and remove dirt. Surfactants have a hydrophobic (anti-water) tail and
a hydrophilic (pro-water) head. Soils are surrounded by the hydrophobic tails of each
surfactant. Water surrounds the hydrophilic head.
TYPES OF SURFACTANTS:
Anionic surfactants have a negative charge on their hydrophilic end. The negative charge
of the surfactant molecules aids in the lifting and suspension of soils in micelles. Anionic
surfactants are commonly employed in soaps and detergents due to their ability to tackle a
wide spectrum of soils.
Nonionic surfactants are nonionic, meaning they have no charge on their hydrophilic end.
Nonionic surfactants are superior to anionic surfactants at emulsifying oils and removing
organic soils. Certain nonionic surfactants are non-foaming or have low foaming properties.
Furthermore, nonionic surfactants have a distinct feature known as a cloud point. The cloud
point is the temperature at which the nonionic surfactant begins to phase separate from the
cleaning solution. The cleaning solution becomes hazy as a result of this. This is considered
the best temperature for detergency. Optimal detergency for low foaming cleansers is at the
cloud point; for foaming cleaners, it is either immediately below the cloud point or at the
commencement of the cloud point.
The cationic surfactants have a hydrophilic end that is positively charged. Because of their
positive charge, they are beneficial in anti-static goods such as fabric softeners. Because
cationic surfactants can act as antibacterial agents, they are frequently utilized in
disinfectants. Cationic surfactants are incompatible with anionic surfactants. Positively
charged cationic surfactants that are combined with negatively charged anionic surfactants
will fall out of solution and become ineffective. Cationic and nonionic surfactants, on the other
hand, are compatible.
Amphoteric surfactants have a positive and negative charge on their hydrophilic end. The
dual charges cancel each other out, resulting in a zwitterionic net charge of zero. The
amphoteric surfactants will respond differently depending on the pH of the solution.
Amphoteric surfactants become positively charged in acidic conditions and behave similarly
to cationic surfactants. They create a negative charge in alkaline liquids, comparable to
anionic surfactants.
4. Differentiate batch and continuous process in soap making and state the advantages and
disadvantages.
In a continuous process, the major reactants or raw materials are continually fed to the reactor
or mixer. Then, even after a specific reaction or process, goods are delivered continuously.
Continuous transport saves money, energy, and time in many applications. A vast number of
products are obtained here. This method is commonly employed in industrial manufacturing.
A batch process, on the other hand, is a process that consists of one or more sequences of
stages that must be completed in a certain order. The raw material is delivered all at once,
and the results are provided after a reaction or a specific process. This procedure must be
carried out again. A complete unit of merchandise is manufactured at one time.
Below are the advantages and disadvantages of both batch and continuous process:
Batch Process
Scheduling is done to
Coordination
maintain the timing
between move to
earth.
Quantities
Produced
products are
span
processing function and they operates in
a steady state.
Large quantities of products are obtained.
produced.
involved if the fouling
expectations are high
Product life
Each machine performs a certain
A whole unit of
Batch process is
Fouling
Continuous Process
Continuous process is involved if fouling
is not considered
Short, 1-2 years
Longer than batch process
Low cost equipment
High cost equipment
Batch process can be
Control batch process requires
controlled very easily
sophisticated control systems
Often
Rare
Cost of
factory
equipment
Controlling
Shut Down
times
Workforce
Small workforce is
needed
Continuous process is generally available
in fully automated plants. If not, large
workforce will be necessary.
5. What are the advantages and disadvantages of soap and detergent especially on
environmental concerns?
Commercial soap manufacture makes use of costly natural resources such as vegetable oil.
Soap necessitates more water for rinsing as well as more energy to heat the wash water.
Detergents often require fewer natural resources in their production, and many surfactants
used today biodegrade swiftly in sewage treatment plants before entering the natural
environment. Another advantage of using soap is that it is completely biodegradable and
derived from natural sources such as vegetable oils and animal fats. Detergent, on the other
hand, has a non-biodegradable, synthetically manufactured branched hydrocarbon chain, and
these compounds can build a thick foam that destroys aquatic life.
6. Draw a simple process flow diagram on soap making indicating the different unit operations
and unit processes and chemical reaction involved.
SOAP MAKING PROCESS FLOW DIAGRAM
SOAP MAKING CHEMICAL REACTION
7. What are the 3 main nutrients of fertilizer and discuss briefly their functions in plant growth?
Nitrogen is regarded as the most vital nutrient, because plants absorb more nitrogen than
any other ingredient. Nitrogen is critical in ensuring that plants are healthy as they develop
and nutritious to eat once harvested. This is because nitrogen is required for the production
of protein, and protein constitutes a large portion of the tissues of most living creatures.
Phosphorus is associated with a plant's ability to utilize and store energy, including the
photosynthesis process. It is also required for plants to grow and develop normally.
Phosphorus is derived from phosphate rock in commercial fertilizers.
Potassium is the third most important nutrient in commercial fertilizers. It improves plant
disease resistance and has a vital role in enhancing crop yields and overall quality. Potassium
also protects the plant in cold or dry weather by strengthening the root system and preventing
wilt.
8.
Give the reactions involved in the Haber and Ostwald Processes.
(in words and chemical formula)
HABER PROCESS:
The Haber Process is utilized in the production of ammonia from nitrogen and hydrogen, and
the parameters used in the process are explained. The process converts nitrogen from the air
into ammonia by combining it with hydrogen supplied primarily from natural gas (methane).
The process is reversible, and the ammonia synthesis is exothermic.
N2(g)+3H2(g)↽−−⇀2NH3(g)
OSTWALD PROCESS:
The Ostwald process is one of the most prevalent ways or chemical processes for
producing nitric acid. In 1902, a German scientist called Wilhelm Ostwald invented the
technique. In 1909, he was awarded the Nobel Prize for his research. It is the simplest
method of producing nitric acid, which is also widely utilized in a variety of applications,
including the manufacturing of fertilizers and inorganic and organic nitrates or nitro
compounds. Typically, the Ostwald process converts ammonia to nitric acid. In this
procedure, vanadium pentaoxide (V2O5) is frequently used as a catalyst during the nitric
acid manufacturing.
Step 1- Catalytic Oxidation Reaction
Primary Oxidation (Formation of Nitric Acid): 4NH3 + 5O2 ↔ 4NO + 6H2O | H -24.8
Kcal/mol
Secondary Oxidation (Formation of Nitrogen Dioxide): 2NO + O2 ↔2 NO2
Step 2 – Absorption of No2 (Formation of HNO3)
3NO2 + H2O -> 2HNO3 + NO
II. Problem Solving on Fertilizer:
1.
An agriculturist needs a fertilizer that is 9% potash, but she can only find fertilizers
that contain 6% and 15% potash. How much of each should she mix to obtain 10
kilograms of fertilizer that is 9% potash?
Given:
A fertilizer = 6% potash
B fertilizer = 15% potash
Total mass= 10kg
Final composition of potash =9%
Asked:
Amount of each fertilizer
Solution:
Let: A= mass of fertilizer A
B= mass of fertilizer B
Component Balance of Potash
B= 10kg-A
0.06𝐴 + 0.15(𝐵) = 0.09(10𝑘𝑔)
0.06𝐴 + 0.15(10𝑘𝑔 − 𝐴) = 0.09(10𝑘𝑔)
A= 6.6666666667kg
A≈6.667kg
Substitution:
B = 10kg-6.667kg
B= 3.3333333333kg
B≈ 3.333kg
∴It needs 6.667 kg of 6% potash and 3.333 kg of 15% potash to obtain 10 kilograms
of fertilizer that is 9% potash
2. If a bag of fertilizer were labeled as containing 35% K2O,
a. What is the analysis when expressed as %K?
Convert %K2O to %K
Atomic Weight: K = 39 g/mol; O = 16 g/mol
Molar Mass: K2O = 2(39 g/mol) + 16 g/mol = 94 g/mol
Proportion of K2O in K=
%𝐾 =
94 𝑔/𝑚𝑜𝑙
2(39𝑔/𝑚𝑜𝑙)
35%
1.20512805
= 1.20512805
= 29.04255319% ≈ 𝟐𝟗. 𝟎𝟒%𝑲
b. Assume the bag is labeled as 150% P, calculate the percentage P2O5 in the
bag.
Convert %P to %P2O5
Atomic Weight: P = 31 g/mol; O = 16 g/mol
Molar Mass: P2O5= 2(31 g/mol) + 5(16 g/mol) = 142 g/mol
Proportion of P2O5in P =
142 𝑔/𝑚𝑜𝑙
2(31𝑔/𝑚𝑜𝑙)
= 2.290322581
%𝑃2 𝑂5 = 150%(2.290322581) = 343.5483871% ≈ 𝟑𝟒𝟑. 𝟓𝟓%𝑷𝟐 𝑶𝟓