Soap is a salt of fatty acids. It is produced by the reaction of fats or oils with sodium hydroxide or potassium hydroxide. Soaps help in removing dirt and grease by dissolving them. Common soaps are sodium stearate, sodium palmitate, etc. Soap works by breaking the bonds between dirt/oil and the surface they are attached to. Their molecules have hydrophilic and hydrophobic regions which allow them to dissolve in water and remove non-water soluble dirt/oil from surfaces and skin.

1.  Q. Define Medicine and
Chemotherapy.
 What is the difference between drugs
and medicines?
 Ans: Chemical substances of natural or
synthetic origin which are used for curing
disease are reducing suffering from pain
are called medicines or drugs.
 The branch of science which deals with
the treatment of disease using suitable
chemicals is known as chemotherapy.

2.  The difference between medicines and
drugs is that medicine are more safe to
use because these have negligible
toxicity and do not cause addiction.eg,
penicillin is called a medicine since it
does not have addiction properties while
heroin is called a drug because of its
pronounced habit forming and addiction
properties

3.  Q. Why do we need to classify drugs in different ways?
 Answer
 The classification of drugs and the reasons for classification are as follows:
 (a) On the basis of pharmacological effect
 This classification is based on pharmacological effect of the drugs. It is useful
for doctors because it provides them the whole range of drugs available for the
treatment of a particular type of problem. For example, analgesics have pain
killing effect, antiseptics kill or arrest the growth of microorganisms. Hence,
such a classification is very useful to doctors.
 (b) On the basis of drug action
 It is based on the action of a drug on a particular biochemical process. For
example, all antihistamines inhibit the action of the compound, histamine
which causes inflammation in the body. There are various ways in which action
of histamines can be blocked. Thus, this classification is important.
 (iii) On the basis of chemical structure:
 This classification provides the range of drugs sharing common structural
features and often having similar pharmacological activity.
 (iv) On the basis of molecular targets:
 This classification provides medicinal chemists the drugs having the same
mechanism of action on targets. Hence, it is the most useful to medicinal
chemists

4.  Q. Explain the term target molecules or drug targets as used in medicinal chemistry.
 Answer
 In medicinal chemistry, drug targets refer to the key molecules involved in certain
 metabolic pathways that result in specific diseases. Carbohydrates, proteins, lipids, and
 nucleic acids are examples of drug targets.
 Drugs are chemical agents designed to inhibit these target molecules by binding with the
 active sites of the key molecules.
 Q. Name the macromolecules that are chosen as drug targets.
 Answer
 The macromolecules chosen as drug targets are carbohydrates, lipids, proteins, and
 nucleic acids.
 Q. Why should not medicines be taken without consulting doctors?
 Answer
 A medicine can bind to more than one receptor site. Thus, a medicine may be toxic for
 some receptor sites. Further, in most cases, medicines cause harmful effects when taken
 in higher doses than recommended. As a result, medicines may be poisonous in such
 cases. Hence, medicines should not be taken without consulting doctors



5.  Q. Define the term chemotherapy.
 Answer
 The use of chemicals for therapeutic effect is
called chemotherapy. For example: the use
 of chemicals in the diagnosis, prevention, and
treatment of diseases

 Q. Which forces are involved in holding the
drugs to the active site of enzymes?
 Answer
 Either of the following forces can be involved in
holding drugs to the active sites of
 enzymes.
 (i) Ionic bonding
 (ii) Hydrogen bonding
 (iii) Dipole − dipole interaction
 (iv) van der Waals force

6.  Q. Discuss Analgesics ii. Antipyretics
iii. Tranquilizers or Hypnotics iv.
Antimicrobials
 v. Antiseptics and Disinfectants
 Ans: i. Analgesics: The chemicals used
for getting relief from pain are called
analgesics. These are of two types
 Narcotics and Non-narcotics.
 Drugs which produce sleep and
unconsciousness are called narcotic
drugs. (e.g. Morphine, codeine,
marijuana etc.).


17.  Non-Narcotic
 Those drugs which do not produce sleep
and unconsciousness are called non-
narcotic drugs .eg. Aspirin (2-
acetoxybenzoic acid) is most commonly
used non-narcotic analgesics alongwith
antipyretic
action.Naproxen,ibuprofen,diclophenac
sodium or potassium are also non-
narcotic drugs.

18.  ii. Antipyretics: The chemical substance
which bring down the body temperature
are called antipyretics.eg, Paracetamol
(N-acetly p-amino phenol), novalgin,etc.
These are drugs also have analgesic
property

19.  iii. Tranquilizers or Hypnotics :The
drugs which act on the central nervous
system and help in reducing stress and
fatigue by indicating a sense of well
being are called tranquilizers.
 Tranquilizers are used for the treatment
mild and severe mental diseases hence,
are called psychotherapeutic drugs. The
most commonly used tranquilizers are
derivatives of barbituric acid viz, veronal,
luminal, seconal, Nembutal etc.

21.  Q. Sleeping pills are recommended by
doctors to the patients suffering from
sleeplessness but it is not advisable
to take its doses without consultation
with the doctor, Why?
 Answer: Most drugs when taken in doses
higher than recommended may cause
harmful effects
 and sometimes, may even lead to death.
Hence, a doctor should always be
consulted before taking any medicine.

23.  Q. Write a short note on
antimicrobials.
 Ans: Drugs used to cure diseases caused
by microbes or microorganisms such as
bacteria, viruses, fungi etc are called
antimicrobials.
 All the microbials diseases are commonly
controlled by following methods
 By using a bactericidal drugs
 By using a bacteriostatic drugs
 By increasing the immunity and resistance
of the body to infection.
 Antibiotics, antiseptics and
disinfectantsare antimicrobial drugs.

24.  Antimicrobials are the drugs used to
fight infectious diseases. They are
classified into four groups
 Antibiotics
 Antivirals
 Antifungals
 Antiprotozoals

25.  Antiseptics and Disinfectants:
 Chemical substances which prevent the
growth of microorganism and may even
kill them, are called antiseptics.
Disinfectants also kill microorganism but
the point of difference from antiseptics is
that they are harmful for living tissues.
 Antiseptics are generally applied on the
wounds, cut, ulcers and diseased skin
surfaces in the form of antiseptic creams
like furacin saframycin.

26.  The same substance can act as antiseptics
as well as disinfectants depending upon
the concentration of the solution used, eg
0.2% solution of phenol acts as antiseptis
whereas its 1% solution acts as
disinfectants.Disecfectants and antiseptics
used in everyday life.

27.  Dettol It is well known antiseptics. It is
the mixture of chloroxylenol and terpineol
in a suitable solvent.
 Salol(phenyl salicylate) it is used as an
intestinal antiseptic for theoat ailmens.
 Lysols cresols (o, m and p-methyl
phenols) in soapy water is called ltsol
and is used as disinfectants.
 Tincture of iodine is a 2 − 3 percent
solution of iodine in alcohol − water
mixture. It is applied to wounds as an
antiseptic

28.  Q.Explain the two types of analgesics.
NBSE 2011,3m
 Ans: The chemicals used for getting relief
from pain are called analgesics. These are of
two types
 Narcotics and Non-narcotics.
 Drugs which produce sleep and
unconsciousness are called narcotic drugs.
(e.g. Morphine, codeine, marijuana etc.).
 ii. Those drugs which do not produce sleep
and unconsciousness are called non-
narcotic drugs .eg. Aspirin (2-
acetoxybenzoic acid) is most commonly used
non-narcotic analgesics alongwith antipyretic
action. Naproxen, ibuprofen, diclophenac
sodium or potassium are also non-narcotic
drugs.

29.  Q. How do antiseptics differ from
disinfectants? Give one example of
each.
 OR.
How are antiseptics distinguished
from disinfectant? Give one example
each. NBSE 2008 , 2m
 OR
 Q. What are antiseptics and
diseinfectants? Give example NBSE
2012, 2m

30.  Answer
 Antiseptics and disinfectants are effective
against micro-organisms. However,
antiseptics
 are applied to the living tissues such as
wounds, cuts, ulcers, and diseased skin
surfaces, while disinfectants are applied to
inanimate objects such as floors, drainage
system ,instruments, etc. Disinfectants are
harmful to the living tissues. Iodine is an
example of a strong antiseptic. Tincture of
iodine (2 − 3 percent of solution of iodine in
alcohol − water mixture) is applied to
wounds. 0.2% solution of phenol acts as
antiseptis whereas its 1% solution acts as
disinfectants. Disinfectants and antiseptics
used in everyday life

33.  Q. Name a substance which can be
used as an antiseptic as well as
disinfectant.
 Answer
 Phenol can be used as an antiseptic as
well as a disinfectant. 0.2 percent solution
of
 phenol is used as an antiseptic, while 1
percent of its solution is used as a
disinfectant.
 What are the main constituents of dettol?
 Answer
 The main constituents of dettol are
chloroxylenol and α-terpineol.

35.  .
 What is tincture of iodine? What is its
use?
 Answer
 Tincture of iodine is a 2 − 3 percent
solution of iodine in alcohol − water
mixture. It is
 applied to wounds as an antiseptic

36.  Q. Write a short note on antibiotics.
 Ans: Many microorganisms produce
certainchemicals which inhibit the growth or
metaabolism of some other
microorganisms.Such chemicals are known as
antibiotics.Now a day’s antibiotics are being
synthesized in laboratories/factories they are
now defined as follows
 “A substance produced wholly or partially by
chemical synthesis which in low concentration
inhibits the growth or destroys microorganisms
by interfering with their metabolic processes is
called antibiotics”.
 The first antibiotics penicillin was discovered by
Alexander Fleming 1929.from mold Penicilium
notatum.
 There are three main sources of antibiotics
 bacteria ii. fungi iii Actinomycetes.

38.  Types of Antibiotics:
 There are two types of antibiotics on the basis of their
mode of action on microorganisms.
 i.Bacteriostatic: these are the antibiotics which retard the
growth of the bacteria eg.erythromycin, tetracycline, and
chloramphenicol.
 ii.Bactericidal: These are those antibiotics which kill the
bacteria. eg. Penicilin, ofloxacin, cephalosporm etc.

 The full range of microorganisms attacked by an
antibiotics is called its spectrum.Antibiotics are of two
types on the basis of number of microorganisms affected
by them.
 Broad spectrum antibiotics: They are effective against
several different types of harmful microorganism.,eg
chloramphenicol, erythromycin, and chloromycetin etc.
 Narrow spectrum antibiotic: They are those which have
specific action ie effective against a short range of
microorganisms eg ampicilin, penicillin. etc.


44.  Ampicilin

49.  Q. What is meant by the term ‘broad
spectrum antibiotics’? Explain.
 Answer
 Antibiotics that are effective against a wide range
of gram-positive and gram-negative
 bacteria are known as broad spectrum
antibiotics. Chloramphenicol is a broad spectrum
 antibiotic.

 It can be used for the treatment of typhoid,
dysentery, acute fever, pneumonia,
 meningitis, and certain forms of urinary
infections. Two other broad spectrum antibiotics
 are vancomycin and ofloxacin. Ampicillin and
amoxicillin −synthetically modified from
 penicillin − are also broad spectrum antibiotics.

50.  Q.Write a short note on anti-fertility
drugs and oral contraceptive pills
 Ans: Chemical substance which are used to
check pregnancy in women are called anti-
fertility drugs or birth control drugs or oral
contraceptives.These control the female
menstrual cycle and ovulation.
 Antifertility drugs contain chemical related
female sex hormones, having a steroid rings
structure.Most of the antifertility drugs
contain a combination of synthetic estrogen
and progesterone derivative which are more
potent than natural hormones.

51.  Oral contraceptive pills:
 These pills contain steroid hormones
which suppress the production of ovum,
and hence prevent pregnancy.
 These pills change the ovulatory cycle.
The birth control pill is essentially a
mixture of synthetic estrogen and
progesterone derivatives.
 Certain Commonly used contraceptive
pills contain Norethindrone ,
Ethynlestradiol and Mifepristone

57.  Q. What are antihistamines?
 Ans: Allergy is caused due to release of
histamine in the body, therefore drugs
used to treat allergy are called anti-
histamine drugs. They are also called
anti-allergic drugs.
 The most commonly used antiallergic
drugs are diphenylhydramine, cetrizine,
chlorpheniramine, etc.

61.  Q.What are food preservatives? Give
example.

 The chemical substances which are added to the
food materials to prevent their spoilage and to
retain their nutritive value for long periods, are
called preservatives.
 Sodium benzoate, Potassium metabisulphite, and
vinegar are the most commonly used food
preservatives.
 -Sodium benzoate is used to prevent fruit juices
and squash as sodium benzoate is soluble in
water.It kills the food spoilage microorganism.It
is metavolized by conversion to hippuric acid
which is ultimately excreted out in the urine.
 -Vinegar is 6-10% solution of acetic acid and it
is used as preservatives for various eatable

64.  Q. What are artificial sweetening
agents? Give two examples.
 Answer

65.  Artificial sweetening agents are chemicals
that sweeten food. However, unlike
natural
 sweeteners, they do not add calories to
our body. They do not harm the human
body.
 Some artificial sweeteners are
aspartame, saccharin, sucrolose, and
alitame.

68.  Saccharin:

69.  Alitame:

70.  Q. Name a sweetening agent used in
the preparation of sweets for a
diabetic patient.
 Answer
 Artificial sweetening agents such as
saccharin, alitame, and aspartame can be
used in
 preparing sweets for diabetic patients.

71.  Q. Name a sweetening agent used in
the preparation of sweets for a
diabetic patient.
 Answer
 Artificial sweetening agents such as
saccharin, alitame, and aspartame can be
used in
 preparing sweets for diabetic patients.

72.  Q. What problem arises in using
alitame as artificial sweetener?
 Answer
 Alitame is a high potency sweetener. It is
difficult to control the sweetness of food
while
 using alitame as an artificial sweetener.

73.  Q. Define soap

74.  Ans: Soap are the sodium or potassium
salts of higher fatty acid having 12-18
carbon atoms.Eg sodium stearate,sodium
palmitate etc.

75.  Q. Write the chemical equation for
preparing sodium soap from glyceryl
oleate and glyceryl palmitate.
 Ans:


77.  Q. Explain the following terms with
suitable examples
 (i) Cationic detergents
 (ii) Anionic detergents and
 (iii) Non-ionic detergents

78.  (i) Cationic detergent
 Cationic detergents are quaternary
ammonium salts of acetates, chlorides, or
bromides.
 These are called cationic detergents
because the cationic part of these
detergents
 contains a long hydrocarbon chain and a
positive charge on the N atom.


80.  (ii) Anionic detergents
 Anionic detergents are of two types:
 1.Sodium alkyl sulphates: These detergents are sodium
salts of long chain alcohols.
 They are prepared by first treating these alcohols with
concentrated sulphuric acid and
 then with sodium hydroxide. Examples of these detergents
include sodium lauryl
 sulphate (C11H23CH2OSO3
 −Na+) and sodium stearyl sulphate (C17H35CH2OSO3
 −Na+).
 2.Sodium alkylbenzenesulphonates: These detergents are
sodium salts of long chain
 alkylbenzenesulphonic acids. They are prepared by Friedel-
Crafts alkylation of benzene
 with long chain alkyl halides or alkenes. The obtained
product is first treated with
 concentrated sulphuric acid and then with sodium
hydroxide. Sodium 4-(1-dodecy)
 benzenesulphonate (SDS) is an example of anionic
detergents

82.  (iii) Non-ionic detergents
 Molecules of these detergents do not
contain any ions. These detergents are
esters of
 alcohols having high molecular mass.
They are obtained by reacting
polyethylene glycol
 and stearic acid.

84.  Q. How are synthetic detergents better than soap?
 OR
 Expalin why synthetic detergents are batter than
soap? NBSE 2011 3m
 Answer
 Soaps work in soft water. However, they are not effective in
hard water. In contrast,
 synthetic detergents work both in soft water and hard
water because they form foam even in hard water.
 Therefore, synthetic detergents are better than soaps.

85.  Q. What are biodegradable and non-
biodegradable detergents? Give one
example of each.
 Answer
 Detergents that can be degraded by
bacteria are called biodegradable
detergents. Such
 detergents have straight hydrocarbon
chains.
 For example: sodium lauryl sulphate

87.  Detergents that cannot be degraded by
bacteria are called non-biodegradable
 detergents. Such detergents have highly-
branched hydrocarbon chains.
 For example:
 sodium -4- (1, 3, 5, 7- tetra methyl octyl)
benzene sulphonate

88.  Q. Why do soaps not work in hard water?
 Answer
 Soaps are sodium or potassium salts of long-chain fatty
acids. Hard water contains
 calcium and magnesium ions. When soaps are dissolved in
hard water, these ions
 displace sodium or potassium from their salts and form
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.


This is the reason why soaps do not work in hard water.

89.  Q. Can you use soaps and synthetic
detergents to check the hardness of
water?
 Answer
 Soaps get precipitated in hard water, but not
in soft water. Therefore, soaps can be used
 for checking the hardness of water.
 However, synthetic detergents do not get
precipitated either in hard water or in soft
 water. Therefore, synthetic detergents cannot
be used for checking the hardness of
 water.


90.  Q. Explain the cleansing action of
soaps.
 Ans Soap molecules form micelles around
an oil droplet (dirt) in such a way that the
hydrophobic parts of the stearate ions
attach themselves to the oil droplet and
the hydrophilic parts project outside the
oil droplet. Due to the polar nature of the
hydrophilic parts, the stearate ions (along
with the dirt) are pulled into water,
thereby removing the dirt from the cloth.

92. 
 Q. Can you use soaps and synthetic
detergents to check the hardness of
water?
 Answer
 Soaps get precipitated in hard water, but not
in soft water. Therefore, soaps can be used
 for checking the hardness of water.
 However, synthetic detergents do not get
precipitated either in hard water or in soft
 water. Therefore, synthetic detergents cannot
be used for checking the hardness of
 water.

93. The END