Question # 1

Density of a gas is usually expressed in

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Kg m³

Kg dm³

g dm^-3

g cm^-3

A state function which describes together the internal energy and product of pressure and volume is called

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Enthalpy

internal energy

Work

Kinetic energy

When water freezes at 0°C, its density decreases due to

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cubic structure of ice

empty spaces present in the structure of ice

change of bond lengths

change of bond angles

Which of the folowing compound is expected to be colored

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Na2SO4

ZnCl2

MgF₂

CuF₂

When liquid solute is dissolved in liquid solvent, then the best unit of concentration is?

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% W/W

% W/V

% V/V

%V/W

Under which conditions real gases deviate from ideal behaviour

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Low temperature and low pressure

Low temperature and high pressure

High temperature and high pressure

High temperature and low pressure

Dehydrogenase is an erample of

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Transferase

Hydrolase

Lyase

Oxido-reductase

The number of molecules in 22.4 dm3 of gas at 0°C and 1 atm are

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6.02×10(23)

6.02× 10(25)

6.02×10(22)

6.02×10(21)

The reaction kinetics concerned with the

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Rate of reaction

Direction of reaction

Factor effecting rate of reaction

both a &b

Esters have fruity smell and are used as artificial favours. Amyl acetate gives flavour of

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Banana

Jasmine

Pineapple

Orange

covalent network of crystals has:

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lower melting point than molecular crystals

higher melting point than molecular crystals

H-bonding

Choose the gas law which gives relationship between volume and pressure:

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Bolye,s law

Graham,s law

Dalton,s law

Charles,s law

Which element differs from rest of elements of its group?

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Ba

Mg

Ca

Be

Amorphous solids

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have sharp melting points

undergo clean cleavage when cut with knife

have perfect arrangement of atoms

can possesses small regions of orderly arrangements of atoms

In which system hydrogen bonding is not present

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solution of ethanol in water

linking of helix in protein molecule

structure of ice

solution of NaCl in benzene

Which of the following undergoes easy dehydration?

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3-MethyIbutan-2-ol

Ethanol

2.Methylpropan-2-ol

Methanol

When 1-butene reacts with bromine, the product formed will be

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1, 3-dihydroxy butane

But-1, 2-diol

1, 3-dihydroxy butan-diol

1,2-dibromo butane

Acetic acid reacts with thionyl chloride to form acetyl chloride, which species acts as nucleophile in the reaction

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SO3

SO2

Cl-

No nucleophile is formed

To which of the following mixtures Dalton's law of partial pressures is not applicable?

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CO and CO₂

CO₂ and N₂

CH₄ and C₂H₆

HCI and NH₃

The value of R in term of dm³torr k^-1mol^-1

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62400

62.4

8.313

0.0821

During sudden expansion of a gas energy is needed to overcome the intermolecular:

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Vibrations

Attractions

Repulsions

All of above

According to kinetic molecular theory, kinetic energy of molecules increases when they are:

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melted from solid to liquid state

frozen into a solid

condensed into liquid

mixed with other molecular at low temperature

Which set of elements is good loser of electrons

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F2. Cl2, Br2

N, P. As

O. S, Se

Li, Na, K

Liquefaction of gas can only be carried out if the:

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without caring for the value critical volume at critical stage

the temperature is more than critical and pressure is 1000 atm

the temperature is below the critical and pressure is very high

temperature is above the critical temperature and pressure can have any value

In order to maintain the boiling point of water at 110 C°, the extemal pressure should be

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550 torr

between 500 and 760 tor

between 760 and 1500 torr

any pressure can be maintained

Which of the following compound is least reactive

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HCHO

CH3CHO

CH3COCH3

C6H5CHO

An ideal gas obeying kinetic gas equation can be liquefied if

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Its temperature is more than critical temperature

Its pressure is more than critical pressure

Its pressure is more than critical pressure but temperature is less than critical temperature

It cannot be liquefied at any value of P and T

In an elimination reaction a more substituted alkene is formed due to the stability associated with

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Free radical

transition state

Activated complex

Carbocation

The partial pressure of 0₂in the lungus is

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116 torr

159 torr

560 torr

760 torr

The temperature of the gas is raised from 27°C to 927°C the root mean square velocity is

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√927/27 times the earlier value

Same as before

Halved

Doubled

Which one among the following is not a good leaving group

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HSO4-

CI-

OH-

Br-

The ratio of close packed atoms to tetrahedral holes in cubic close packing is

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1 : 1

1 : 2

1 : 3

2 : 1

Dipole-dipole forces and London forces are collectively called

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hydrogen bonding

Vander Waals forces

Covalent bonding

Ionic bonding

Which of the following is not a postulate of the kinetic theory of gases?

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when gas particles collide, their total kinetic energy increases

gases consist of molecules in a constant state of random motion

when gas particles collide their total kinetic energy does not change at all

The gas particles travel in straight lines unit they collide with one another or with the walls of the container

Dipole-dipole forces are present between:

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non-polar molecules

polar molecules

both polar and non-polar

none pf above

Carboxylic acids reacts with sodium carbonate, & gas evolved in this reaction

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CO2

H2

CO

Both a &b

The conversion of molecules of A to B follows a second order kineties. Doubling the concentration of A will inerease the rate of formation of B by a factor of

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2

4

1/2

1/4

In a crystal the atoms are locate at the position of:

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infinite potential energy

minimum potential energy

Zero potential energy

maximum potential

During esterifcation, the alcobol molecule acts as:

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Oxidizing agent

Electrophile

Reducing agent

Nucleophile

Greater shielding effect corresponds to ionization potential value

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greater

lesser

remain same

no effect

The electrochemical reactions occurring at both the electrodes along with the electrolytic conduction constitute

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Oxidation

reduction

Redox reaction

electrolysis

The highest temperature in which a substance can exist as a liquid is called its

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Absolute temperature

Critical temperature

Maximum temperature

Body temperature

When two ice cubes are pressed together they unite to form one cube. Which of the following forces is responsibles for holding them together

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Van der Waal's

covalent bonding

hydrogen bonding

dipole-dipole interaction

When light is exposed to transtion element, then electrons jump from lower orbitals to higher orbitals in

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Orbitals of s-subshell

Orbitals of d-subshell

Orbitals of p-subshell

between different shells

Which of the following factors does not affect the SN1 rate is

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Nucleophilicity of the attacking nucleophile

Stability of the carbonium ion

Solvent system

The nature of leaving group

The average kinetic energy of an ideal gas per molecule is SI units at 25°C will be

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6.17 x 10^-21 KJ

6.17 x 10^-21 J

6.17 x 10^-20 J

7.16 x 10^-20 J

When calcium formate and calcium acetate are dry heated they form

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НCOOH

C2H5OH

CH3CHO

HCHO

During combustion analysis, which one is used for absorbing carbon dioxide:

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50% KOH

5% KOH

Mg(ClO4)2

Silica gel

For what value of Kc almost forward reaction is complete

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Kc.=10(-30)

Kc.=1

Kc = 10(30)

Kc,=0

In an electrochemical series, elements are arranged on the basis of

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pH scale

pKa scale

pOH scale

Hydrogen scale

Consider gas is measure in bars then the units of rate of reaction is

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Mole dm-3 sec

Bars sec

Mole dm-3 sec-1

Bars sec-1

Which class of compound cannot show positional isomerism?

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Alkanes

Alkene

Alkynes

Alcohol

Which of the following is more reactive where 0-H bonds break

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P°alcohol

T° alcohol

S°alcohol

Cannot be predicated

If 250 cm³of hydrogen gas is cooled from 127°C to -73°C at constant pressure then new volume of gas is ______ dm³

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0.25

0.375

0.125

0.0625

The best concentration unit used for K⁺ ions present in potable water is

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ppm

Mole fraction

Molarity

Molality

An ideal gas expands according to PV=constant. On expansion, the temperature of gas

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will rise

will drop

cannot be determined because the exteral pressure is not known

will remain same

Acetaldchyde and ketone form addition product with

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Phenyl hydrazine

Hydroxylamine

Hydrazine

hydrogen cyanide

The ratio of most probable velocity to that of average velocity is

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π/2

2/π

√π/2

If pressure is increased from a 2 atm to 4 atm on a gas then its volume will decrease from:

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3L to 1L

4L to 2L

6L to 4L

8L to 2L

The maximum possible number of hydrogen bonds in which a H₂O molecule can participate is

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1

2

3

4

An amine is produced in the following reaction
C2H5l+2NH3-------C2H5NH2 +NH4l. What is mechanism?

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Electrophilic addition

Electrophilic substitution

Nucleophilic addition

Nucleophilic substitution