ecat chemistry past papers Mcqs

1

A toxic chemical is defined as a material that is?

A

Highly flammable

B

Radioactive

C

Poisonous and causes serious health problems

D

Causes suffocation

2

Which of the following is an example of a toxic chemical mentioned in the text?

A

Acetone

B

Mercury

C

Helium

D

Nitrocellulose

3

Reactive chemicals may cause fires and explosions because they can evolve?

A

Water vapor

B

Oxygen

C

Dangerous gases

D

Harmless fumes

4

Which type of radiation causes external injuries?

A

Alpha particles

B

Beta particles

C

Gamma rays

D

Neutrons

5

Asphyxiation is a hazard caused by a lack of which gas?

A

Carbon dioxide

B

Nitrogen

C

Oxygen

D

Argon

6

Which of the following is an example of an asphyxiant chemical?

A

Acetic acid

B

Benzoyl peroxide

C

Carbon monoxide

D

Caustic alkalies

7

The hazard sign with a skull and crossbones indicates what type of hazard?

A

Radiation Hazard

B

Toxic Hazard

C

Corrosive Hazard

D

Flammable Hazard

8

What does PPE stand for in a laboratory context?

A

Personal Protective Equipment

B

Primary Prevention Equipment

C

Public Protective Equipment

D

Practical Protective Equipment

9

Which piece of equipment is essential for controlling a small fire in the lab?

A

Emergency shower

B

Fume hood

C

Portable fire extinguisher

D

Beaker of water

10

In case of a fire emergency, what is the first recommended action?

A

Run out of the lab immediately

B

Stay calm and do not panic

C

Start cleaning your workspace

D

Continue your experiment

11

What type of chemicals are picric acid and nitrocellulose examples of?

A

Corrosive

B

Toxic

C

Flammable

D

Explosive

12

Which chemical property is described by having a flashpoint around room temperature?

A

Corrosiveness

B

Toxicity

C

Flammability

D

Reactivity

13

Mineral acids, such as HF, and caustic alkalies are examples of what type of hazard?

A

Corrosive Hazard

B

Explosive Hazard

C

Radiation Hazard

D

Asphyxiation Hazard

14

What should you do if you are exposed to a corrosive chemical?

A

Ignore it

B

Wait for a teacher

C

Wash the affected area with soap and water

D

Apply another chemical to neutralize it

15

Calcium hydride, Na, and Li are examples of which type of chemical?

A

Toxic chemicals

B

Reactive chemicals

C

Asphyxiant chemicals

D

Corrosive chemicals

16

What is the primary danger of alpha and beta particles?

A

They cause external burns

B

They cause extreme damage when inhaled or injected

C

They are highly flammable

D

They deplete oxygen levels

17

What is a symptom of a decreasing oxygen level due to asphyxiants?

A

Slow breathing

B

Low heart rate

C

Feeling of extreme cold

D

Rapid breathing and nausea

18

The 'Warning' sign on a chemical bottle signifies that the chemical can cause?

A

Less serious injury

B

Serious injury

C

No injury

D

Only property damage

19

Safety in the chemistry laboratory is considered to be?

A

The students' responsibility only

B

The professor's responsibility only

C

The lab incharge's responsibility only

D

A shared responsibility

20

The label 'Corrosive' on a chemical bottle indicates that the material?

A

Is an oxidizing agent

B

Can explode

C

Destroys living tissue on contact

D

Degrades rapidly upon exposure

21

Picric acid is an example of what type of chemical?

A

Highly toxic

B

Self-reactive

C

Flammable liquid

D

A strong base

22

What should you do in case of a fire drill in the lab?

A

Run to the safety shower

B

Climb into the fume cupboard

C

Close gas valves and turn off all equipment

D

Carry chemicals out of the lab

23

What is the recommended method for smelling a gas?

A

Inhale deeply from the container

B

Heat the gas first

C

Waft the fumes towards your nose

D

Ask someone else to smell it

24

Why should flammable liquids not be stored in a refrigerator?

A

They will freeze

B

The refrigerator can provide an ignition source

C

They will lose their flammability

D

They will corrode the refrigerator

25

Where should experiments with corrosive chemicals be conducted?

A

On an open bench

B

Near a window

C

In a fume hood

D

Outside the laboratory

26

Which of these is NOT an example of Personal Protective Equipment (PPE)?

A

Lab coat

B

Protective glasses

C

Mobile phone

D

Face shield

27

According to the text, laboratory accidents often result from?

A

Using too much chemical

B

Working too quickly

C

Failure to follow instructions

D

Having too much light

28

What is the purpose of placing warning signs in a laboratory?

A

To decorate the lab

B

To ensure every person understands and acts accordingly for safety

C

To list the chemicals available

D

To show the lab's achievements

29

Benzoyl peroxide is given as an example of which two types of hazards?

A

Toxic and Corrosive

B

Explosive and Reactive

C

Flammable and Asphyxiant

D

Radiation and Toxic

30

What is the primary safety measure for handling reactive chemicals?

A

Handling them with bare hands

B

Mixing them quickly

C

Handling them with utmost care and segregation

D

Using glassware without any protection

31

What should be used to monitor exposure to radiation?

A

A thermometer

B

A barometer

C

Badges

D

A pH meter

32

If a chemical is inhaled, what is the first step to take?

A

Give the person water

B

Make the person lie down

C

Remove the patient from the contaminated area

D

Ignore it unless symptoms appear

33

Periodic drills with compulsory participation are held for what purpose?

A

To practice experiments

B

To handle emergency situations

C

To clean the laboratory

D

To test new equipment

34

What is the rule for disposing of non-hazardous laboratory chemical waste?

A

Pour it down any drain

B

It can be disposed of in a sewer or trash bin

C

It must be transported to a special site

D

It should be stored indefinitely

35

How is hazardous waste material handled for disposal?

A

It is neutralized and poured into the sewer

B

It is buried in the lab's backyard

C

It is transported to a hazardous waste disposal site

D

It is burned in the fume hood

36

Which of the following is NOT listed as a flammable compound?

A

Ethers

B

Methylated spirit

C

Picric acid

D

Acetone

37

Acetic acid (glacial) is given as an example of what kind of hazard?

A

Toxic

B

Corrosive

C

Reactive

D

Explosive

38

To avoid breathing corrosive vapours, corrosive chemicals must be used in a?

A

Well-lit area

B

Fume cupboard

C

Large beaker

D

Sealed container

39

Medical x-rays produce what type of radiation that can affect living tissues?

A

Non-ionizing radiation

B

Alpha radiation

C

Ionizing radiation

D

Beta radiation

40

Which hazard is associated with a gas or vapour causing unconsciousness or death through suffocation?

A

Toxic Hazard

B

Asphyxiation Hazard

C

Reactive Hazard

D

Corrosive Hazard

41

What item of PPE is specifically mentioned for use with corrosive chemicals instead of just safety glasses?

A

Heavy gloves

B

Splash goggles and a face shield

C

Hearing protection

D

Steel-toed boots

42

To confine a fire, what action is recommended?

A

Open all doors and windows

B

Close doors

C

Pour water on all equipment

D

Turn on the ventilation system

43

The text advises students not to work alone in the lab and to perform experiments in the presence of whom?

A

Lab instructor and other laboratory staff

B

Only other students

C

Only the principal

D

Security guard

44

What must be done before using any equipment in the lab?

A

It must be washed with acid

B

It must be polished

C

It should be checked to see if it's working properly

D

It should be weighed

45

When should you seek immediate medical help according to the safety instructions for toxic chemicals?

A

Only after finishing your experiment

B

If you think you may have been exposed

C

The next day

D

Only if you feel severe pain

46

Cathode rays were discovered during experiments with a...?

A

Gold foil

B

Cloud chamber

C

Discharge tube

D

Spectrometer

47

Which particle is approximately 1836 times heavier than an electron?

A

Neutron

B

Proton

C

Nucleus

D

Alpha particle

48

The charge on a cathode ray particle (electron) is...?

A

Positive

B

Neutral

C

Negative

D

Variable

49

Who discovered the proton?

A

J.J. Thomson

B

Chadwick

C

Rutherford

D

E. Goldstein

50

Canal rays are streams of...?

A

Electrons

B

Positively charged ions

C

Neutrons

D

Photons

51

Which fundamental particle has no charge?

A

Electron

B

Proton

C

Neutron

D

Ion

52

According to Rutherford's model, the central part of an atom is called the...?

A

Orbit

B

Shell

C

Nucleus

D

Electron cloud

53

Protons and neutrons within the nucleus are held together by...?

A

Gravitational force

B

Electrostatic force

C

Weak nuclear force

D

Strong nuclear force

54

The path of an electron in an atom is best described as...?

A

A fixed circular orbit

B

A fixed elliptical orbit

C

A probabilistic path

D

A straight line

55

The first shell or K shell can accommodate a maximum of how many electrons?

A

8

B

2

C

18

D

32

56

The formula to calculate the maximum number of electrons in a shell is...?

A

n^2

B

2n

C

2n^2

D

n+1

57

Which sub-shell is present in the first energy level (n=1)?

A

p sub-shell

B

s sub-shell

C

d sub-shell

D

f sub-shell

58

The third shell (n=3) consists of which sub-shells?

A

s, p

B

s, p, d, f

C

s, p, d

D

s only

59

The atomic number (Z) of an element represents the number of...?

A

Neutrons

B

Electrons in the outer shell

C

Protons

D

Protons and neutrons

60

The mass number (A) of an element is the sum of...?

A

Electrons and protons

B

Protons and neutrons

C

Electrons and neutrons

D

Only neutrons

61

How can the number of neutrons (N) in an atom be calculated?

A

N = A + Z

B

N = Z - A

C

N = A - Z

D

N = A

62

An atom of Carbon-12 (^12_6C) contains how many protons?

A

12

B

18

C

6

D

0

63

An atom of Uranium-238 (^238_92U) contains how many neutrons?

A

92

B

238

C

330

D

146

64

Atoms of the same element with the same number of protons but different numbers of neutrons are called...?

A

Ions

B

Molecules

C

Isomers

D

Isotopes

65

Which isotope of hydrogen does not contain a neutron?

A

Deuterium (^2H)

B

Tritium (^3H)

C

Protium (^1H)

D

Hydrogen-4

66

Isotopes of an element have different...?

A

Chemical properties

B

Atomic numbers

C

Number of protons

D

Physical properties

67

The process where an unstable nucleus emits radiation is called...?

A

Ionization

B

Radioactive decay

C

Nuclear fusion

D

Chemical reaction

68

Technetium-99m is a radioactive isotope used for...?

A

Carbon dating

B

Generating nuclear power

C

Medical diagnostic imaging

D

Testing metal strength

69

Radiocarbon dating uses the radioactive isotope...?

A

Uranium-238

B

Tritium

C

Carbon-14

D

Krypton-85

70

The mass of an atom is primarily concentrated in its...?

A

Electrons

B

Outermost shell

C

Nucleus

D

Sub-shells

71

The particles discovered by Goldstein in a discharge tube with a perforated cathode were called...?

A

Cathode rays

B

X-rays

C

Canal rays

D

Beta particles

72

The mass of a neutron is almost the same as the mass of a...?

A

Electron

B

Proton

C

Helium nucleus

D

Two electrons

73

In a neutral atom, the number of electrons is equal to the number of...?

A

Neutrons

B

Mass number

C

Protons

D

Shells

74

The symbol for the mass number is...?

A

N

B

Z

C

M

D

A

75

What is the relative mass of an electron?

A

~1 amu

B

~1836 amu

C

Very small, almost negligible

D

Equal to a proton

76

How many electrons can the 'p' sub-shell accommodate at most?

A

2

B

10

C

6

D

14

77

Elements in the periodic table are arranged according to their...?

A

Mass number

B

Number of neutrons

C

Atomic number

D

Number of isotopes

78

The relative atomic mass scale is based on which isotope?

A

Hydrogen-1

B

Oxygen-16

C

Carbon-12

D

Uranium-235

79

An atom that loses an electron becomes a...?

A

Anion (negative ion)

B

Cation (positive ion)

C

A different element

D

An isotope

80

What is the charge of a proton in Coulombs?

A

-1.6022 x 10^-19 C

B

+1.6022 x 10^-19 C

C

0.0

D

9.109 x 10^-31 C

81

What is the mass of a proton in Kg?

A

9.109 x 10^-31 Kg

B

1.675 x 10^-27 Kg

C

1.673 x 10^-27 Kg

D

1.6022 x 10^-19 Kg

82

Which shell has a higher energy level?

A

K shell

B

L shell

C

The one closer to the nucleus

D

All shells have equal energy

83

The isotope Tritium (^3H) is...?

A

Stable

B

Non-existent

C

Radioactive

D

An ion

84

The process of removing an electron from an atom is called...?

A

Decay

B

Reduction

C

Ionization

D

Fusion

85

Who conducted the gold foil experiment to discover the nucleus?

A

Dalton

B

Thomson

C

Rutherford

D

Goldstein

86

The 'd' sub-shell can hold a maximum of how many electrons?

A

2

B

6

C

10

D

14

87

Which of these is an application of radioactive isotopes?

A

Creating alloys

B

Purifying water

C

Diagnosing thyroid disorders

D

Manufacturing plastics

88

An oxygen atom with 8 protons and 8 neutrons would be symbolized as...?

A

16O

B

8O

C

24O

D

16/8O

89

The L-shell corresponds to which principal quantum number 'n'?

A

n=1

B

n=2

C

n=3

D

n=4

90

The positive ions produced in a discharge tube that travel towards the cathode are known as...?

A

Cathode rays

B

Electrons

C

Anode rays

D

Neutrons

91

According to the uncertainty principle, for an electron, we cannot precisely know both its...?

A

Mass and charge

B

Path and location

C

Speed and mass

D

Energy and spin

92

Which element's isotope is the standard for relative atomic mass?

A

Hydrogen

B

Helium

C

Oxygen

D

Carbon

93

Which statement about isotopes is true?

A

They have different numbers of electrons.

B

They have different chemical behaviors.

C

They have the same number of protons.

D

They have the same mass number.

94

Which of the following is NOT a primary type of chemical bond mentioned in the text?

A

Ionic bond

B

Covalent bond

C

Hydrogen bond

D

Metallic bond

95

An ionic bond is described as a strong electrostatic attraction between what?

A

Two nuclei

B

Shared electrons and a nucleus

C

Oppositely charged ions

D

Delocalized electrons and cations

96

How is a covalent bond defined in the chapter?

A

Transfer of electrons

B

Attraction between oppositely charged ions

C

Strong electrostatic attraction between shared electrons and two nuclei

D

Sea of delocalized electrons

97

What do atoms do to lower their energy and increase stability?

A

Isolate themselves

B

Increase their kinetic energy

C

Combine with other atoms

D

Shed all their electrons

98

Which noble gas is noted for having two electrons in its outer shell, following the duplet rule?

A

Neon (Ne)

B

Argon (Ar)

C

Helium (He)

D

Krypton (Kr)

99

What does a sodium atom do to achieve a stable electronic configuration?

A

Gain seven electrons

B

Lose one electron

C

Share one electron

D

Lose two electrons

100

A chemical bond formed by the complete transference of an electron from one atom to another is called?

A

A covalent bond

B

A metallic bond

C

A coordinate covalent bond

D

An ionic bond

CHEMISTRY MCQs

A toxic chemical is defined as a material that is?

Which of the following is an example of a toxic chemical mentioned in the text?

Reactive chemicals may cause fires and explosions because they can evolve?

Which type of radiation causes external injuries?

Asphyxiation is a hazard caused by a lack of which gas?

Which of the following is an example of an asphyxiant chemical?

The hazard sign with a skull and crossbones indicates what type of hazard?

What does PPE stand for in a laboratory context?

Which piece of equipment is essential for controlling a small fire in the lab?

In case of a fire emergency, what is the first recommended action?

What type of chemicals are picric acid and nitrocellulose examples of?

Which chemical property is described by having a flashpoint around room temperature?

Mineral acids, such as HF, and caustic alkalies are examples of what type of hazard?

What should you do if you are exposed to a corrosive chemical?

Calcium hydride, Na, and Li are examples of which type of chemical?

What is the primary danger of alpha and beta particles?

What is a symptom of a decreasing oxygen level due to asphyxiants?

The 'Warning' sign on a chemical bottle signifies that the chemical can cause?

Safety in the chemistry laboratory is considered to be?

The label 'Corrosive' on a chemical bottle indicates that the material?

Picric acid is an example of what type of chemical?

What should you do in case of a fire drill in the lab?

What is the recommended method for smelling a gas?

Why should flammable liquids not be stored in a refrigerator?

Where should experiments with corrosive chemicals be conducted?

Which of these is NOT an example of Personal Protective Equipment (PPE)?

According to the text, laboratory accidents often result from?

What is the purpose of placing warning signs in a laboratory?

Benzoyl peroxide is given as an example of which two types of hazards?

What is the primary safety measure for handling reactive chemicals?

What should be used to monitor exposure to radiation?

If a chemical is inhaled, what is the first step to take?

Periodic drills with compulsory participation are held for what purpose?

What is the rule for disposing of non-hazardous laboratory chemical waste?

How is hazardous waste material handled for disposal?

Which of the following is NOT listed as a flammable compound?

Acetic acid (glacial) is given as an example of what kind of hazard?

To avoid breathing corrosive vapours, corrosive chemicals must be used in a?

Medical x-rays produce what type of radiation that can affect living tissues?

Which hazard is associated with a gas or vapour causing unconsciousness or death through suffocation?

What item of PPE is specifically mentioned for use with corrosive chemicals instead of just safety glasses?

To confine a fire, what action is recommended?

The text advises students not to work alone in the lab and to perform experiments in the presence of whom?

What must be done before using any equipment in the lab?

When should you seek immediate medical help according to the safety instructions for toxic chemicals?

Cathode rays were discovered during experiments with a...?

Which particle is approximately 1836 times heavier than an electron?

The charge on a cathode ray particle (electron) is...?

Who discovered the proton?

Canal rays are streams of...?

Which fundamental particle has no charge?

According to Rutherford's model, the central part of an atom is called the...?

Protons and neutrons within the nucleus are held together by...?

The path of an electron in an atom is best described as...?

The first shell or K shell can accommodate a maximum of how many electrons?

The formula to calculate the maximum number of electrons in a shell is...?

Which sub-shell is present in the first energy level (n=1)?

The third shell (n=3) consists of which sub-shells?

The atomic number (Z) of an element represents the number of...?

The mass number (A) of an element is the sum of...?

How can the number of neutrons (N) in an atom be calculated?

An atom of Carbon-12 (^12_6C) contains how many protons?

An atom of Uranium-238 (^238_92U) contains how many neutrons?

Atoms of the same element with the same number of protons but different numbers of neutrons are called...?

Which isotope of hydrogen does not contain a neutron?

Isotopes of an element have different...?

The process where an unstable nucleus emits radiation is called...?

Technetium-99m is a radioactive isotope used for...?

Radiocarbon dating uses the radioactive isotope...?

The mass of an atom is primarily concentrated in its...?

The particles discovered by Goldstein in a discharge tube with a perforated cathode were called...?

The mass of a neutron is almost the same as the mass of a...?

In a neutral atom, the number of electrons is equal to the number of...?

The symbol for the mass number is...?

What is the relative mass of an electron?

How many electrons can the 'p' sub-shell accommodate at most?

Elements in the periodic table are arranged according to their...?

The relative atomic mass scale is based on which isotope?

An atom that loses an electron becomes a...?