Text Book Back Questions and Answers - Chapter 15 - Chemistry in Everyday Life - 12th Chemistry Guide Samacheer Kalvi Solutions

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Chemistry in Everyday Life
TextualEvaluation Solved
Multiple Choice Questions
Question 1.
Which of the following is an nalgesic?
(a) Streptornycin
(b) Chloromycetin
(c) Asprin
(d) Penicillin
Answer:
(c)Asprin
Question 2 .
Dettol is the mixture of
(a) Chioroxylenol and bithionol
(b) Chioroxylenol and a - terpineol
(c) phenol and iodine
(d) terpineol and bithionol
Answer:
(b) Chioroxylenol and a - terpineol
Question 3.
Antiseptics and disinfectants either kill or prevent growth of microorganisms. Identify which of the following statement is not true.
(a) dilute solutions of boric acid and hydrogen peroxide are strong antiseptics
(b) Disinfectants harm the living tissues
(c) A $0.2 \%$ solution of phenol is an antiseptic while $1 \%$ solution acts as disinfectant
(d) Chlorine and iodine are used as strong disinfectants
Answer:
(a) dilute solutions of boric acid and hydrogen peroxide are strong antiseptics
Question 4.
Saccharin, an artificial sweetener is manufactured from
(a) cellulose
(b) toluene
(c) cyclohexene
(d) starch
Answer:
(b) toluene

Question 5 .
Drugs that bind to the receptor site and inhibit its natural function are called
(a) antagonists
(b) agonists
(c) enzymes
(d) molecular targets
Answer:
(a) antagonists
Question 6.
Aspirin is a/an
(a) acetylsalicylic acid
(b) benzoyl salicylic acid
(c) chlorobenzoic acid
(d) anthranilic acid
Answer:
(a) acetylsalicylic acid
Question 7.
Which one of the following structures represents nylon 6,6 polymer?

Answer:

Question 8 .
Natural rubber has
(a) alternate cis - and trans - configuration
(b) random cis - and trans-configuration
(c) all cis - configuration
(d) all trans - configuration
Answer:
(c) all cis - conflguration
Question 9.
Nylon is an example of
(a) polyamide
(b) polythene
(c) polyester
(d) poly saccharide
Answer:
(a) polyamide
Question 10.
Terylene is an example of
(a) polyamide
(b) polythene
(c) polyester
(d) poly saccharide
Answer:
(c) polyester
Question 11 .
Which is the monomer of neoprene in the following?

Answer:

Question 12 .
Which one of the following is a bio-degradable polymer?
(a) HDPE
(b) $\mathrm{PVC}$
(c) Nylon 6
(d) PHBV
Answer:
(d) PHBV
Question 13.
Non stick cook wares generally have a coating of a polymer, whose monomer is
(a) ethane
(b) prop - 2 - enenitrile
(c) chioroethene
(d) 1,1,2,2-tetrafluoroethane
Answer:
(d) 1,1,2,2-tetrafluoroethane
Question 14.
Assertion: 2-methyl - I ,3-butadiene is the monomer of natural rubber
Reason: Natural rubber is formed through aniònic addition polymerisation.
(a) If both assertion and reason are true and reason is the correct explanation of assertion
(b) if both assertion and reason are true but reason is not the correct explanation of assertion
(c) assertion is true but reason is false
(d) both assertion and reason are false
Answer:
(c) assertion is true but reason is false
Question 15.
An example of antifertility drug is
(a) novesirol
(b) seldane
(c) salvarsan
(d) Chioramphenicol
Answer:
(a) novestrol
Question 16.
The drug used to induce sleep is
(a) paracetamol
(b) bithional
(c) chioroquine
(d) equanil
Answer:
(d) equanil
Question 17.
Which of the following is a co - polymer?

(a) Orlon
(b) $\mathrm{PVC}$
(c) Teflon
(d) PHBV
Answer:
(d) PHBV
Question 18.
The polymer used in making blankets (artificial wool) is
(a) polystyrene
(b) PAN
(c) polyester
(d) polythene
Answer:
(b) PAN
Question 19.
Regarding cross-linked or network polymers, which of the following statement is incorrect?
(a) Examples are Bakelite and melamine
(b) They are formed from bi and tri-functional monomers
(c) They contain covalent bonds between various linear polymer chains
(d) They contain strong covalent bonds in their polymer chain
Answer:
(d) They contain strong covalent bonds in their polymer chain
Question 20 .
A mixture of chioroxylenol and terpinecol acts as
(a) antiseptic
(b) antipyretic
(c) antibiotic
(d) analgesic
Answer:
(a) antiseptic
II. Answer the following questions
Question 1.
Which chemical is responsible for the antiseptic properties of dettol?
Answer:
1. Chloroxylenol and
2. Terpineol are the chemicals responsible for the antiseptic properties of dettol. But among these two, chloroxylenol plays more important role. Chioroxylenol is an antiseptic and disinfectant which is used for skin disinfection and cleaning surgical instruments.

Question 2.
What are antibiotics?
Answer:
Antibiotics is a chemical substance produced by one microorganism, that selectively inhibits the growth of another micro organism. Example : penicillins and cephalosporins.
Question 3.
Name one substance which can act as both analgesic and antipyretic.
Answer:
Aspirin (acetylsalicylic acid) is a chemical substance which lowers body temperature (to normal) and also reduces body pain. Therefore it acts as both antipyretic and analgesic.
Question 4.
Write a note on synthetic detergents.
Answer:
1. Synthetic detergents are formulated products containing either sodium salts of alkyl hydrogen suiphates or sodium salts of long chain alkyL benzene suiphonic acids.
2. Synthetic detergents are three types. They are
- anionic detergents - sodium lauryl sulphate.
- Cationic detergents $-\mathrm{n}$ - hexadecyltrimethyl ammonium chloride.
- Non-ionic detergents - Pentaerythrityl stearate.
3. Synthetic detergents can be used even in hard water, while soaps cannot be used in hard water.
4. The cleansing action of detergents are similar to the cleansing action of soaps.
5. When detergents are dissolved in water its hydrocarbon part attaches itself to grease and oil particles. Whereas its ionic part remains attached to water. Therefore when dirty clothes are agitated in solution of detergents then dirty particles sticks to the hydrocarbon part of detergents and at the same time the water loving ionic part pulls away this dirt from clothes.
Question 5.
How do antiseptics differ from disinfectants?
Answer:
An tisep tics
1. Antiseptics are chemical substance which prevent the growth of micro organizers and may even kill them but are not harmful to living tissues.
2. They are generally applied to living tissues such as wounds, cuts bulks and diseased surfaces.
3. All the antiseptics are disinfectants.

4. They are not ingested or swallowed.
5. e.g., Povidone - iodine, Benzalkonium - Chloride
Disinfectants
1. Disinfectants are chemical substances which kill microorganism or stop their growth but are harmful to human tissues.
2. Disinfectants are applied to inanimated objects such as floors, drainage system, instruments etc.
3. All the disinfectants are not antiseptics.
4. They can be injected or swallowed.
5. e.g. Alcohol, chlorine compunds.
Question 6.
What are food preservatives?
Answer:
Food preservatives are chemical substances are capable of inhibiting, retarding or arresting the process of fermentation, acidification or other decomposition of food by growth of micro organisms.
Examples:
1. Acetic acid is used mainly as a preservative for preparation of pickles.
2. Sodium meta suiphite is used as preservative for fresh vegetables and fruits.
3. Sodium benzoate is used as preservative for juices.
Question 7.
Why do soaps not work in hard water?
Answer:
Soaps are sodium or potassium salts of long - chain falty acids. Hard water contains calcium and magnesium
ions. When soaps are dissolved in hard water, these ions displace sodium or potassium from insoluble calcium or magnesium salts of fatty acids. These insoluble salts separate as scum.

This is the reason why soaps do not work in hard water.
Question 8.
What are drugs? How are they classified?
Answer:
A drug is a substance that is used to modify or explore physiological systems or pathological states for the benefits of the recipient. it is used for the purpose of diagnosis, prevention cure or relief of a disease.
Classification of drugs:
Drugs care classified based on their proportions such as chemical structure, pharmacological effect, target system, site of action etc.
1. Classification based on the chemical structure:
In this classification, drugs with a common chemical skelton are classified into a single group. For example, ampicillin, amoxicillin, methiceillin etc. all have similar structure and are classified into a single group called penicillin.
Similarly we have other group of drugs such as opiates, steroids, catecholamines etc. Compounds having similar chemical structure are expected to have similar chemical properties. However, their biological actions are not always similar.
2. Classification based on the pharmacological effect:
- In this classification, the drugs are grouped based on their biological effect that they produce on the recipient.
- For example, the medicines that have the ability to kill the pathogenic bacteria are grouped as antibiotics.
- This kind of grouping will provide the full range of drugs that can be used for a particular disease.
3. Classification based on the target system:
- In this classification, the drugs are grouped based on the biological system (or) process that they target in the recipient
- This classification is more specific than the pharmacological classification.
- For example, the antibiotics streptomycin and erythromycin inhibit the protein synthesis (target) in bacteria and are classified in a same group. However their mode of action is different.
- Streptomycin inhibits the initiation of protein synthesis, while erythromycin prevents the incorporation of new aminoacids to the protein.
4. Classification based on the site of action:
1. The drug molecule interacts with biomolecules such as enzymes, receptors etc, which are referred as drug targets.
2. We can classify the drug based on the drug target with which it binds.
3. This classification is highly specific compared to the others. These compounds often have a common mechanism of action, as the target is the same.
Question 9.

How the tranquilizers work in body?
Answer:
1. They are neurologically active drugs.
2. Tranquilizer acts on the central nervous system by blocking the neurotransitter dopamine in the brain.
3. This drug is used for treatment of stress anxiety, depression, sleep disorders and severe mental diseases like schizophrenia.
Question 10.
Write the structural formula of aspirin.
Answer:

Question 11.
Explain the mechanism of cleansing action of soaps and detergents.
Answer:
Mechanism of cleansing action of soaps and detergents:
1. The cleansing action of both soaps and detergents from their ability to lower the surface tension of water, to emulsify oil or grease and to hold them in a suspension in water.
2. This ability is due to the structure of soaps and detergents.
3. In water a sodium soap dissolves to form soap anions and sodium cations. For example, the following chemical equation shows the ionisation of sodium palmitate.

4. A soap anion consists of a long hydrocarbon chain with a carboxylate group on one end. The hydrocarbon chain, which is hydrophobic, is soluble in oils or grease. The ionic part is the carboxylate group which is hydrophilic, is soluble in water.

5. In water, detergent dissolves to form detergent anions and sodium cations. For example the following chemical equations show the ionisation of sodium alkyl sulphate and sodium alkyl benzene sulphate.

6. The following explains the cleansing action of a soap or detergent on a piece of cloth with a greasy stain.
1. A soap or detergent anion consists of a hydrophobic part and a hydrophilic part.
2. Soap or detergent reduces the surface tension of water. Therefore the surface of the cloth is wetted thoroughly.
3. The hydrophobic parts of the soap or detergents anions are soluble in grease.
4. The hydrophilic parts of the anions are soluble in water.
5. Scrubbing or mechanical agitation helps to pull the grease away from the cloth and the grease is broken into smaller droplets.
6. Repulsion between the droplets causes the droplets to be suspended in water, fonning an emulsion.
7. Thus the droplets do not coagulate or,redeposit on the cloth. Rinsing washes away the droplets.
Question 12 .
Which sweetening agent are used to prepare sweets for a diabetic patient?
Answer:
Artificial sweetening agents such as,
1. saccharin
2. Alitame
3. Aspartame
can be used in preparing sweets for diabetic patients.
Question 13.
What are narcotic and non - narcotic drugs. Give examples.
Answer:
1. Narcotic drug is an addictive drug that reduces pain, induces sleep and may alter mood or behaviour. Example: Morphine and codeine.
2. Non - narcotic drug are chemical substance (medications) used to control pain and inflammation. They are available at drugstores without a prescription or by prescription when given at higher doses. Example:
Acetaminophen and paracetamol.
Question 14.
What are anti fertility drugs? Give examples.
Answer:
Artificially drugs are chemical substances which suppress the action of hormones that promote pregnancy. These drugs actually reduce the chances of pregnancy and act as a protection. Antifertility drugs are made up of derivatives of synthetic progesterone or a combination of derivatives of oestrogen and progesterone.
Example: Ethynylestradiol, menstranol and norcthynodrel etc.

Question 15 .
Write a note on co - polymer.
Answer:
1. A polymer containing two or more different kinds of monomer units is called a co-polymer.
2. Co-polymers have properties quite different from the homopolymers.
3. The structural units of co-polymers are derived from the different monomers may be present in regular, alternation or in random order or strings of several units of one kind may alternate with strings of another.
4. For example, Buna $-S$, Buna $-N$, Nylon $-6,6$ etc. Buna $-S$ contains styrene and butadiene monomer units.
Question 16.
What are bio degradable polymers? Give examples.
Answer:
1. The materials that are readily decomposed by micro organisms in the environment are called biodegradable.
2. Natural polymers degrade on their own after certain period of time but the synthetic polymers do not.
3. The biopolymers which disintergrates by themselves in biological systems during a
4. certain period of time by enzymatic hydrolysis and to some extent by oxidation are called biodegradable polymers.
Examples:
1. Polyhydroxy butyrate (PHB)
2. Polyhydroxy butyrate - co - hydroxyl valerate (PHBV)
3. Polylactic acid (PLA)
Question 17.
How is terylene prepared?
Answer:
The monomers are ethylene glycol and terephthalic acid or dimethýlterephthalate. When these monomers are mixed and heated at $500 \mathrm{~K}$ in the presence of zinc acetate and antimonytrioxide catalyst, terylene (or dacron) is formed.

Question 18.
Write a note on vulcanization of rubber.
Answer:
1. Natural rubber is very soft and brisky. it has high water absorption capacity and low tensile strength. Its properties can be improved by a process called vulcanization.
2. Natural rubber is mixed with $3-5 \%$ sulphur and heated at $100-150^{\circ} \mathrm{C}$ causes cross linking of the cis 1,4 polyisoprene chains through disuiphide $(-\mathrm{S}-\mathrm{S}-)$ bonds.
3. The physical properties of rubber can be altered by controlling the amount of sulphur that is used for vulcanization. When 3 to $10 \%$ sulphur is used the resultant rubber is somewhat harder but flexible.
4. Following properties of rubber $\mathrm{CH}_3$

Question 19.
Classify the following as linear, branched or cross linked polymers
1. Bakelite
2. Nylon
3. polvthene
Answer:
1. Bakelite - cross linked polymer
2. Nylon - Linear polymer
3. Polythene - Linear polymer
Question 20.
Differentiate thermoplastic and thermosetting.
Answer:
Difference between thermoplastic and thermosetting:
Thermoplastic
1. They soften on heating and harden on cooling, and they can be remoulded.
2. They consists of linear long çhain polymers and low molecular weights polymers.
3. All the polymer chains are held together by weak Vanderwaals forces.
4. They are weak, soft and less brittle.
5. They are formed by additon polymerisation
6. They are soluble in organic solvents.
7. Example: PVC, polythene, polystrene etc.
Thermosetting
1. They do not soften on heating and they cannot be remoulded.
2. The consist of three dimensional network structure and high molecular weight polymers.
3. All the polymer chains are linked by strong covalent.
4. They are strong, hard and more brittle.
5. They are formed by condensation polymerisation.
6. They are insoluble in organic solvents.
7. Example: Bakelite, melamine etc.