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Lucent's General Knowledge > Chemistry > Flashcards

Chemistry Flashcards

1
Q

Who is the father of Mordern Chemistry?

A

Lavoisier (1743-1793)

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2
Q

Early Indian philosophers classified matter in the form of what?

A

5 basic elements - Panch Tatava

Air, earth, fire, sky and water

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3
Q

Indian sage________________ was perhaps the first to suggest that all forms of matter are composed of very small particles known as ___ and each ___ may be made up of still smaller particles called ___________

A

Maharishi Kanada
anu
anu
parmanu

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4
Q

Who named tiny particles parmanu as atoms from the Greek word atom meaning ______

A

Domocritus

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5
Q

Matter divisions:

A

Physical Classification
solid liquid gas

Chemical classification
Pure substances, Mixuture

element compound
metallic metalloids Non-metallic

organic inorganic

Homogeneous Heterogeneous

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6
Q

What are the fourth and fifth states of matter?

A

fourth-plasma
fifth-bose-einstein condensation state

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7
Q

Plasma state

A

consists of super energetic and super excited particles. These particles are in the form of ionized gases. Plasma can occur when matter is heated to a very high temperature. The matter in the plasma state is a collection of free highly energetic and highly excited electrically charged particles.

The fluorescent tubes and neon sign bulbs contain inert gases, when electric current is passed through them they produce glowing plasma, having a characteristic colour depending upon the nature of the gas.

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8
Q

It is the presence of ________ that makes CFL tube glow

A

Plasma

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9
Q

In _____ on the basis of statistical calculation, ___________ gave the concept of the fifth state of matter.

A

1920
Satyendra Nath Bose

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10
Q

The Bose-Einstien state is formed how?

A

supercooling a gas of extremely low density, about one hundred thousand of the density of normal air, to super low temperature.

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11
Q

Approximate relative abundance of some elements in the earth crust in percentages

A

Oxygen - 46.6
Silicon - 27.7
Aluminum - 8
Iron - 5
Calcium - 3.6
Potassium - 2.8
Magnesium - 2.1
Hydrogen - 0.14
Phosphorous - 0.12

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12
Q

The conductivity of metal decreases with __________________ due to _________________

A

increase in temperature
vibration of positive ions at their Lattice points

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13
Q

Non-Metals does not posses lusture except
bad conductors of electricity except

A

Iodine
Graphite

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14
Q

Approximate percentage of elements in human body

A

Oxygen - 65
Carbon - 18
Hydrogen - 10
Nitrogen - 3
Calcium - 2
Phosphorous - 1
Potassium - 0. 35
Sodium - 0.15
Chlorine - 0.15
Magnesium - 0.05
Iron - 0.0004

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15
Q

Organic is now applied to ______ and their ______

A

hydrocarbons
derivatives

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16
Q

The process of direct conversion of vapour into solid is called

A

Hoar Frost

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17
Q

Crystallization process

A

This method is mainly used for the separation and purification of solid substances. In this process, the impure solid or mixture is heated with a suitable solvent to its boiling point and the hot solution is filtered. The clear filtrate is cooled slowly to room temperature when the pure solid crystallizes out. This is separated by filtration and dried.

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18
Q

Crystallization done in different time intervals is called

A

fractional crystallization

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19
Q

Distillation used to separate two or more volatile liquid which have different boiling points

A

Fractional distillation

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20
Q

The name chromatography is derived from

A

Latin word -Chroma meaning color.

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21
Q

Chromatography

A

is based on the difference in the rates at which the components of a mixture are absorbed in the suitable absorbent

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22
Q

What are the types of Chromatography

A

a. Column (absorption) Chromatography
b. Thin layer chromatography
c. Paper chromatography
d. High-pressure liquid chromatography
e. Ion-exchange chromatography
f. Gas Chromatography

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23
Q

The boiling point of Ethanol

A

78.3C

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24
Q

The boiling point of Chloroform

A

62C

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25
Boiling point of Acetone
46C
26
The boiling point decreases with
decrease in atmospheric pressure
27
____________ increases the boiling point
Soluble impurities
28
Evaporation causes ___________. and why
cooling molecules having higher kinetic energy escape from the surface of the liquid
29
What are the factors that affect evaporation
Nature of liquid Temperature Surface Area
30
What are the factors that affect evaporation?
Nature of liquid Temperature Surface Area
31
Vapour pressure is directly related to
temperature
32
Vapour pressure depends on
Its nature temperature
33
In ---- to ---- atomic theory had been given by ___ _____
1803 to 1808 John Dalton
34
Daltons theory consists of
1. Elements consist of minute, indivisible, indestructible particles called atoms 2. Atoms of an element are identical to each other. They have the same mass and size. 3. Atoms of different elements differ in properties and have different masses and sizes. 4. Atoms can not be created, destroyed or transformed into atoms of other elements
35
Smallest particle of an element is
Atom
36
_____ is the smallest particle of an element or compound that can have a stable and independent existence.
Molecule
37
A Mole is a collection of
6.023 X 10^23 particles
38
What is Avogardo's Number
6.023 X 10^23
39
Atomic mass | formula
(Mass of one atom of the element)/ (1/12 X Mass of one atom of Carbon - 12 ) ## Footnote Molecular mass is the same but is compared to mass of the carbon
40
Electron was discovered by
J.J Thomson
41
The name electron was given by
Stoney
42
What is the relative charge of an electron absolute charge absolute charge in e.s.u (electrostatic unit)
-1 -1.6 X 10^-19 coulomb -4.8 X 10 ^-10 e.s.u
43
The relative mass of an electron is __________ Its absolute mass is (in grams and kg)
0.000543 amu 9.1 X 10^-28g 9.1 X 10^-31kg
44
Charge mass ration
Coulomb/Gram
45
The charge mass (e/m) ratio of an electron is
-1.76 X 10^8
46
A proton had been discovered by
Goldstein
47
A proton was named by
Rutherford
48
The relative charge on proton is ______ and its absolute charge is _________ Coulomb or _________ e.s.u
+1 +1.6 X 10 ^-19 Coulomb + 4.8 X 10 ^-10 e.s.u
49
The relative mass of proton is _____________ amu and its absolute mass is ___________ gram or ___________kg
1.00763 1.673 X 10 ^ -24 1.673 X 10 ^ -27
50
The charge/mass (e/n) ratio for a proton is
9.58 X 10 ^ 4
51
An electron was obtained from
Cathode Ray experiment
52
A proton was obtained from
Anode Ray experiment
53
A neutron had been discovered by
James Chadwick
54
The relative mass of neutron is _______ amu and its absolute mass is _________ gram or __________kg
1.00863 1.675 X 10 ^-24 1.675 X 10 ^-27
55
1K=
-273C
56
Atomic number is denoted by
Z
57
Z=
e=p | When e is number of electrons; p is number of protons
58
A neutron was obtained from
radioactivity phenomenon | 9Be4 +4He2(alpha) ----------->12C6 + 1n0
59
According to __________ law atomic number of an element is more fundamental property than its atomic mass
Mosely's
60
Mass number is
The sum of protons and neutrons denoted by A A=p+n
61
23NA11
Mass number is up Atomic number is down
62
Isotopes
Same atomic number but different mass number Same element
63
Isotopes of carbon are
12C6, 13 14
64
Isotopes of Hydrogen are
1H1, 2, 3 | protium, deuterium, tritium
65
Which is the radioactive isotope of hydrogen
Tritium
66
In isotope what changes
neutrons protons remains the same
67
Isobars
Same mass number but different atomic number Different elements, cannot be same
68
Isobars
Same mass number but a different atomic number Different elements, cannot be the same 40Ar18, 40K19, 40Ca20
69
Isotones
Atoms of different elements having the same number of neutrons 14C6, 15N7, 16O8
70
Isoelectronic
These are atoms/molecules/ions containing the same number of electrons
71
Alpha particles
doubly positively charged He++ is called alpha particle ## Footnote In chemistry, an alpha particle is a type of ionizing radiation consisting of two protons and two neutrons bound together into a particle identical to a helium nucleus. It is represented by the symbol α . Alpha particles are emitted by some radioactive materials such as uranium and radium. They have a positive charge and are relatively large and heavy compared to other types of radiation such as beta particles and gamma rays. Alpha particles can be stopped by a sheet of paper or the outer layer of human skin but can be harmful if ingested or inhaled .
72
Thomsons model of an atom
According to JJ Thomson, an atom is treated as sphere of radius 10^-8 cm in which positively charged particles are uninformally distributed and negatively charged electrons are embedded through them. This is also called **Plum -Pudding model** of an atom or a water-melon model of an atom
73
Rutherford’s Model of a atom
On the basis of scattering experiment, Rutherford proposed a model of the atom which is known as nuclear atomic model. *According to this model* 1. An atom consists of a heavy positively charged nucleus where all protons and neutrons are present. Protons and neutrons are collectively called nucleons. Almost whole mass of the atom is contributed by these nucleons. 2. Radius of nucleus = 10^-13 cm Radius of an atom = 10^-8 cm Radius of an atom = 10^5 times of the radius of the nucleons 3. Volume of an atom is 10^15 times heavier than volume of a nucleus. 4. Electrons revolve around the nucleus is closed orbits with high speed. This model is similar to the solar system, the nucleus representing the sun and revolving electrons as planets. The electrons are therefore, generally referred as planetary electrons. Rutherford’s a-scattering experiment was responsible for the discovery of proton. I., prositively charged nuclear at the centre of atom

Lucent's General Knowledge (10 decks)

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