1.
PHARMACEUTICAL
CHEMISTRY-l
Last 5 years objective type questions with answers
Compiled by
Mr. Sachinkumar Pandey

2.
Explain the following terms.
i) Achlorhydria-
Achlorhydria is a condition in which there is absence or insufficient secretion of hydrochloric
acid in stomach. The symptoms of achlorhydria vary in patients.
Common symptoms of achlorhydria are
 mild diarrhoea, abdominal pain, sensitivity to spicy foods, loss of appetite etc.
 The lack of secretion of hydrochloric acid thus causes gastrointestinal disturbances.
ii) Emetics- These are the agents which induce vomiting. They produce their action directly by
stimulating chemoreceptor trigger zone (CTZ) or by directly irritating intestinal mucosa.
iii) Astringents- In general term, astringents are the compounds that bring about mild protein
precipitation. This action may be on mucosal membrane when taken internally or on skin for
topical use. Astringents when applied topically cause precipitation of protein of surface cell by
coagulation. The action depends upon the extent of penetration of agent and the type of
chemical action resulting with protein.

3.
Define
Radio activity:-
The phenomenon of spontaneous and continuous emission of radiations by
radioactive isotopes is known as radioactivity.
Half-life:-It is the time taken for half of the radioactive nucleoid to disintegrate.
OR
It is defined as the time in which amount of radioactive nucleoid disintegrate to half
of its initial value.

4.
Define the terms with examples
Lewis Acid and Lewis Base
Definition of Lewis Acid:-
An acid is an electron pair acceptor or acid is electron seeking species or electrophilic
species.
Ex.H+,Na+,K+,Mg+,Al+,BF3,FeCl3
Definition of Lewis Base:-
A base is an electron pair donor and which have unshared electron pairs to share with
proton or nucleophilic species.
Ex. H2O,OH-,,F-,CH3COOO-,SO4,NH3

5.
Define the terms with examples
Respiratory stimulants- Respiratory stimulants increases Pulmonary ventilation by
their effect on depth and rate of respiration by stimulating respiratory centres in the
medulla
Examples- Gaseous ammonia, Dilute Ammonia solution, Ammonium carbonate etc.
Inhalants
Inhalants are gaseous substances directly administered by nasal or oral respiratory
route for its local or systemic effect. OR Inhalants are drugs or chemicals which in
vapour form are inhaled in the body.
E.g. - Oxygen, Carbon dioxide, Nitrous oxide, Hydrogen, Nitrogen etc.

6.
Define and classify “Topical Agents” with
examples.
Topical agents: Topical agents are compounds or preparations applied locally on the surface of skin or mucous
membranes. OR
Topical agents are substance applied on body surface, including application within the body cavities that open to the
outside. E.g. oral, vaginal, colonal, nose, ear, rectum etc.
Classification:
1. Protectives & Adsorbents: Talc, Zinc oxide, calamine, Zinc stearate, Titanium dioxide, Silicon polymers etc.
2. Antimicrobial agents:
a) Compounds acting by oxidation: Hydrogen peroxide, Potassium permanganate,Chlorinated lime
b) Compounds acting by halogenation: Iodine preparations e.g. Iodine, povidone iodine, Chlorinated lime, Sodium
Hypochlorite
c) Compounds acting by Protein precipitation: Silver nitrate, Mild silver protein, Mercury & mercury compounds like
yellow mercuric oxide, Ammoniated mercury, Boric acid, Borax
3. Sulfur & its compounds: Sublimed sulfur, Precipitated sulfur, Selenium sulphide
4. Astringents: Alum, Zinc sulphate, Aluminium chloride, etc.

7.
Explain
 Write incompatibilities of the following.
 (i) Sulphur dioxide:- Sulphur dioxide being a reducing agent, it is general
incompatible
 with oxidising agents. Its bleaching action is able to remove colour from the
preparation
 and other alkalis.
 (ii) Silver nitrate:- It is incompatible with halides like Cl-, Br-, I, and organic
compound,
 tannis etc.

8.
Define “Astringents”. Mention their uses.
Astringents are the agents which cause local or surface or mild protein precipitation when
applied to damaged skin or mucus membrane.
Astringent uses:
1. It causes constriction of small blood capillaries, and promote the coagulation of blood
hence used as styptic (able to stop bleeding).
2. It decreases the volume of exudate from wounds & skin eruption.
3. Astringent causes constriction of skin pores & destroy body odor, hence used as an
antiperspirant& deodorant.
4. Higher concentration of astringent is used to remove warts (extra growth of cell on
skin).
5. It promotes healing and toughens the skin.
6. It restricts blood flow to the surface of mucous membrane hence astringent decreases
inflammation.

9.
Write the chemical incompatibilities of the
following.
i) Hypophosphorus acid-
Since Hypophosphorus acid is reducing agent, it gets readily oxidised by usual oxidizing
agents. Mercury, Silver, bismuth, lead salts are reduced partly to metallic state exhibiting
darkening in color and partial precipitation.
ii) Sulphur dioxide -
Sulphur dioxide being a reducing agent, it is in general incompatible with oxidizing
agents and thiamine. Its bleaching action removes color from the preparation.
iii) Ferrous Sulphate-
Ferrous Sulphate is incompatible with alkali and gets oxidised in air easily in presence of
arsenates and mercuric salts. It is also incompatible with phosphates, tannates and
benzoates.

10.
Give synonym for the following.
i) Magnesium sulphate- Epsom Salt.
ii) Sodium potassium tartarate- Rochelle salt, Seignette salt, Potassium sodium tartarate.
iii) Precipitated sulphur- Milk of sulphur.

11.
Write the molecular formula for the
following.
i) Sodium Metabisulphite- Na2S2O5
ii) Calcium Carbonate- CaCO3
iii) Stannous Fluoride- SnF2.

12.
Give synonyms and molecular formula for
i) Sodium Hydroxide:
Synonym-Caustic soda
Molecular formula- NaOH
ii) Chlorinated lime
Synonym - Bleaching powder
Molecular formula - CaOCl2

13.
Discuss uses of the following compounds.
Sodium Nitrite-
• It is used as an antidote in cyanide poisoning.
• It is used as antioxidant.
• Due to its vasodilation action, it is considered effective in angina pectoris.
• It is used as food preservative.
Sodium Acetate –
• Is used as systemic alkaliniser.
• It is an ingredient of peritoneal dialysis fluid.
• It is used as diuretic.
• Is used to prepare buffer solutions.

14.
Discuss uses of the following compounds.
Sodium Thiosulphate-
• It is used as an antioxidant.
• Is used in parasitic skin diseases.
• Is used in controlling infection to athlete’s foot.
• It is effective in cyanide poisoning.
• It is used extensively in photographic industry

15.
Discuss uses of the following compounds.
Magnesium Trisilicate
• It is used as an antacid in the treatment of peptic ulcers.
• It also used gastrointestinal protective agent with colloidal silica, which can
coat gastrointestinal mucosa conferring further protection.
• It can also be used in oral pharmaceutical formulations and food products as
a glidant.
• It is used as a food additive.
Stannous fluoride:-
It is used to prevent dental caries, single application of 8% solution of stannous
fluoride to the tooth surface sufficient for 6 month.

16.
Discuss the uses of boric acid.
Uses-
• Boric acid is used in preparation of buffer solution.
• It is used to maintain acidic pH in various topical medications.
• Boric acid is used in ointment for emollient & antiseptic action.
• Boric acid solutions are used mainly as eye & mouth wash for local anti-
infective action.
• Since boric acid has smooth unctuous nature it is employed as an
ingredient in dusting powder.

17.
Discuss the effect of heat on boric acid.
Effect of heat on boric acidi)
• When heated above 100°C, it dehydrates, forming metaboric acid (HBO2):
H3BO3 → HBO2 + H2O
• Boric acid melts at about 160°C, forming tetra boric acid or pyro boric acid
(H2B4O7):
4 HBO2 → H2B4O7 + H2O
• When heated above 160°C further dehydrates, forming boron trioxide.
H2B4O7 → 2 B2O3 + H2O

18.
Write properties of calcium hydroxide.
Properties-
• It occurs as white, soft powder.
• It is odourless.
• It has alkaline and slightly bitter taste.
• It is slightly soluble in water, soluble in aq. solutions of glycerine and
sugar.
• Solubility of calcium hydroxide diminishes with increasing temp.

19.
Write uses of calcium hydroxide.
Uses-
• It acts as an antacid
• Used as an astringent in infantile diarrhea & vomiting in the form of lime
water.
• It reacts with fatty acids, forming calcium soaps which act as emulsifying
agent.
• It is an ingredient in some skin lotions.
• Calcium hydroxide along with sodium hydroxide in a particular mixture known
as
• Soda Lime is used for its ability to absorb CO2 from expired air.
• Its CO2 absorbing property is useful in certain types of gas traps.

20.
Write properties, storage and handling of
NaOH.
Properties-
• It occurs as white sticks, pellets, scales or masses,it is highly deliquescent
powder.
• It is strongly alkaline.
• When exposed to air, it rapidly absorbs moisture and CO2.
• It is soluble in boiling water, alcohol, glycerin.
• When it is dissolved in water, considerable heat is generated.
Storage and handling-
• It is stored in tightly closed container as it absorbs moisture and CO2. It should
not be touched with hands but handled with spatula.

21.
Explain
i) Limit tests:-
Limit tests are quantitative or semi-quantitative tests designed to identify and control small
quantities of impurity which are likely to be present in the substance.
ii) Significant figures:-
The number of significant figures is the number of digits which are necessary to express results
which are consistent with the precision of the measurement.

22.
Define expectorants. Write mechanism of action
of expectorants with example.
Expectorant: The drugs that remove sputum from the respiratory tract. These drugs either
increase the fluidity of sputum or increase the volume of fluids that are to be expelled from
the respiratory tract by coughing. Expectorants are used orally to stimulate the flow of
respiratory tract secretions.
Mechanism of action of expectorants:
Mechanism of action of expectorants is categories in two ways that is sedative type and
Sedative type :-It acts by reflex action by irritating the gastric mucosa and thereby
stimulating respiratory tract secretion. Ex. Ammonium chloride, Potassium iodide.
Stimulant type:- These drugs bring about a stimulation of the secretory cells of the
respiratory tract directly or indirectly, since the drug stimulates secretion, more fluid is
produced in respiratory tract and sputum gets diluted. Ex.Terpenoid oils like Eucalyptus,
Lemon

23.
Write importance of sodium ion in the
body fluid.
• The main component of the extracellular fluid is sodium ion which is
associated with chloride and bicarbonate in regulating the acid base
balance.
• It helps in the maintenance of osmotic pressure of various body fluids.
• It is of vital importance in preserving normal irritability of muscle and
permeability of cell.
• It plays important role in the transmission of nerve impulses in the nerve
fibres.

24.
Classify antacids with examples
Classification of antacids is as follows:
A) Systemic/ Absorbable antacids- E.g. Sodium Bicarbonate
B) Non systemic/ Non absorbable antacids:
 Aluminium containing antacids- E.g. Aluminium Hydroxide, Aluminium
Phosphate, Basic aluminium carbonate
 Calcium containing antacids- E.g. Calcium carbonate, Calcium Phosphate
 Magnesium containing antacids- E.g. Magnesium carbonate, Magnesium oxide,
Magnesium hydroxide, Magnesium trisilicate
C) Combination antacids- E.g. Aluminium Hydroxide and Magnesium hydroxide,
Aluminium Hydroxide gel and Magnesium trisilicate.

25.
Write properties of ideal antacids.
Properties of ideal requirements of an antacids:-
• It should not be absorbable and cause systemic alkalosis.
• It should not be laxative or cause constipation.
• It should exert effect rapidly & over a long period of time.
• It should buffer in pH 4-6.
• It should not produce large volume of gas.
• It should be palatable & inexpensive.
• It should probably inhibit pepsin.
• It should be insoluble in water & have fine particle size.
• It should not have side effects.

26.
Write two properties of Aluminium
hydroxide gel.
Properties of Aluminium hydroxide gel-
i) It is aqueous white viscous suspension of hydrated Al2O3 with
Aluminium carbonate or bicarbonate.
ii) Its pH is 5.5 to 8.0.
iii) It contains sodium benzoate as preservative, oil of mentha or
peppermint oil as flavouring agent and sucrose or sorbitol as sweetening

27.
Write uses and storages and labeling of Oxygen.
Oxygen:
Storage and labeling - Oxygen is stored and supplied in metallic cylinder under pressure and
pressure gauge. The shoulder of the cylinder is painted white and the remainder is painted black.
The name and symbol of oxygen O2 is stenciled on the cylinder. It should be stored in special
cool room which is free from inflammable chemicals.
Uses –
i. It is used in hypoxia for artificial respiration.
ii. It is used as inhalant for supporting respiration during anesthesia.
iii. Therapeutically, it is used in treatment of anoxia, anemia, stagnant type anoxia, asphyxia
and in histotoxic conditions.
iv. It is used in asthma, shock and poisoning due to Carbon monoxide or barbiturates.
v. O2 mixed with 5-7% CO2 is used as respiratory stimulant.

28.
Write the molecular formula for the
following.
i) Sodium Metabisulphite- Na2S2O5
ii) Calcium Carbonate- CaCO3
iii) Stannous Fluoride- SnF2.