Question # 1

The most complex strueture a single polypetide can assume is

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1° structure

2°structure

3° structure

4° structure

Halogens form halogen acids. HF is the weakest among all of them This is due to the reason that

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fluorine is a very small-sized atom

fluorine is highly electronegative atom

there is strong hydrogen bonding in HF

the polarity of HF bond is less

The enzymes that bring about exchange of functional groups like phosphate are called

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Ligases

Lyases

Isomerases

Transferases

Which of the following pairs of not form a dative covalent bond to each other?

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NH₃ and H⁺

H₂O and H⁺

NH₃ and BF₃

CH₄ and AICI₃

Theoretically, the temperature at which volume of gas become equal to zero is called

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Boiling point of water

Zero absolute

Zero Kelvin

both B and C

The forces present between the ions and water molecules are called:

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dipole-dipole forces

dipole-induced dipole forces

London dispersion forces

ion-dipole forces

K2SO4, and K2Cr2O4, are isomorphous solids and exist in

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cubic form

orthorhombic form

trigonal form

tetragonal

The cause of deviation form ideal behaviour is because

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the actual volume of gas molecules is not negligible

there is force of attraction between molecules of a gas

both a and b

none of these

Which class of compound cannot show positional isomerism?

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Alkanes

Alkene

Alkynes

Alcohol

Correct statement about Nucleophilic substitution bimolecular is

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Transition state is formed

Inversion take place

It is two step reacticn

Both a &c

A real gas most closely approaches the behaviour of an ideal gas at

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15 atm. and 200 K

1 atm. and 273 K

0.5 atm.and 500 K

15 tm, and 500 K

In which of the following techniques rate of reaction is directly related with number ofions

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Spectrometry

Dilatometric method

Conductometric method

Refractometric method

The structure of protein helps protein to

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be in proper shape

attach substrate

perform is function

All of these

The conversion of tertiary alcohols into alkenes in the presence of K2Cr2O7 + H2SO4 is

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Addition reaction

C-H bond cleavage

Elimination reaction

Combustion reaction

In van der Waal's equation of state of the gas law,the constant 'b' is measure of

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Intermolecular repulsions

Intermolecular collisions per unit volume

Volume occupied by the molecules

Intermolecular attraction

The pH of neutral water is 6.8 then the temperature of H2O is

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25°C

More than 25°C

less than 25 C°

Not predicted

Freshly cut metals have a shining surface because

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electrons excited, then excited electrons release energy as light

metals have brittle nature

metals conductivity increases

metals are malleable and ductile

The densities of two gases are in the ratio of 1 : 16.The ration of their rates of diffusion is

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16 : 1

4 : 1

1 : 4

1 : 16

The amount of heat required to vaporize one mole of liquid at its boiling point without change in temperature is called

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molar heat of vaporization

molar heat of sublimation

molar heat of fusion

none of these

What is the formula of silica?

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Si2O3

SiO2

Si3O4

SiO-

One of the following can produce greater number of moles of ethyl chloride on reacting with escess of ethanol

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PCI5

PCI3

HCI/ZnCl2

SOCI2

At compromise distance the forces dominating between atoms are

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repulsive forces

attractive forces

Dipole induced dipole force

H-bonding

An organic compound made from oxidation of ethanol is

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Formic acid

Acetic acid

Malonic acid

Citric acid

SN2-reactions can be usually observed in

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Primary alkylı halide

secondary alkyl halide

Tertiary alkyl halide

Both A. and B

Amorphous means

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arranged

ordered

shaped

shapeles (no arrangements)

AgNO₃ is a polymorphic having two different crystalline forms which are

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cubic, tetragonal

monoclinic, hexagonal

cubic, orthorhombic

orthorhombic, rhombohedral

Propanone does not undergo

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Oxime formation

Reduction of Fehling solution

Hydrazone formation with hydrazine

Reaction with HCN

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

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Banana

Jasmine

Pineapple

Orange

What is the weight of 10 dm³of CO₂at 27°C and 2 atm?

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89.3 g

56.1 g

125 g

127 g

Formation of Picric acid from phenol needs heating, one possible reason for it is

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acidity of phenol

e- donating nature of-OH

acidity of picric acid

e- with drawing effect of- NO2

A line parallel to x-axis is obtained when graph is drawn between

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Volume on abscissa & pressure on ordinate

Volume on abscissa & PV on ordinate at all conditions

Pressure on abscissa & PV on ordinate at constant temperature

None of these

Diamond and silicon carbide are insoluble in all solvents because

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they have high melting and boiling points

absence of three electrons

they are huge giant three dimensional molecules (macromolecules)

their unit cells have tetrahedral geometry

Which of the following does not represent a type of crystal system

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Triclinic

Monoclinic

Rhombohedral

Isotropical

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No of unpaired electrons are maximum in

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V+3

Mn+2

Fe+3

Cr+3

The enzyme which is found in saliva, accelerates the conversion of starch into sugar is

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Pepsin

Thrombin

Ptyalin

Fumarase

Which of the statement is applicable for both ideal and real gases molecules?

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Have no forces of attraction

Collisions between the molecules is elastic

Molecules are in random movement

The actual volume of gas is negligible as compared to the volume of gas

A graph is plotted, P on x-axis and V on y-axis for a given mass at constant temperature, we shall get:

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a curve with different peaks

a curve called isotherm

straight line parallel to x-axis

a straight line

The Sl mechanism for the hydrolysis of an alkyl halide to an alcohol involves the formation of

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Carbocation

Carbanion

Pentavalent carbon in the transition state

Free radical

Which of the following belongs to alkaline earth metals

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Cu

Zn

Sn

Mg

Which of the following does not give flame test?

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Li

Ba

Mg

Sr

When a compressed gas is allowed to expand into a region of low pressure, it produce:

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Vapours

Cooling effect

Heating effect

None of above

The law of distribution of energy is given by

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Clausius

Maxwell

Bernoulli

Boltzmann

Which volume of gas has minimum value

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Apparent volume

Actual volume

Excluded volume

All have equal value

In dilatometric method is directly proportional to extent of reaction

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Change in concentration

Change in pressure

Chang in volume

Change in temperature

What does no happen when an ideal gas is heated?

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an increase in the average energy of the gas particles

an expansion in the range of kinetic energies possessed by particles

an increase in the number of molecules with lower energies

a drop in the number of molecules with lower energies

When the concentration of reactants is taken as unity the rate of reaction is equal to

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average rate

concentratian of reactant

instantaneous rate

specific rate constant

The spreading of ink on blotting paper is due to

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capillary action

hydrogen bonding

intermolecular forces of the ink

intermolecular forces of the ink and paper

The deviation of a gas from ideal behaviour is maximum at

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-10°C and 5.0 atm

100°C and 2.0 atm

-10°C and 2.0 atm

0°C and 2.0 atm

Spectrometry method is applicable if a reactant or a product absorbs radiation

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Ultraviolet

Visible

Infrared

Any of these

which of the following d blocks element can showthe highest oxidation number is its ompound

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Chromium

iron

Copper

Manganese

For an endothermic reaction, enthalpy of reactants

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Is smaller than that of the products

Is greater than that of the products

Must be greater or smaller than that of the products

Is equal to that of the products

Under what conditions do real gases show close to ideal gas behavior?

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low pressure, low temperature

high pressure, low temperature

low pressure, high temperature

high pressure, high temperature

Which is the following would have most like an ideal gas at room temperature?

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carbon dioxide

helium

hydrogen

nitrogen

What water freezes at 0∘ , Its density decreases dues to:

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cubic structure of ice

empty spaces present in the structure

change of bond lengths

change of bond angles

Buffer solutions are used in except

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Clinical analysis

Nutrition

Soil science

Qualitative analysis

London forces are more affective at

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low temperature

high temperature

low pressure

low temperature and high pressure

About 25% of earth crust mass is made up of element

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Oxygen

Silicon

Aluminium

Aluminates

The hetero atom in py ridine is

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Oxygen

Nitrogen

Chlorine

Sulphur

The number of molecules in one dm³of water is close to:

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6.02/22.4 x10²³

12.04/22.4 x10²³

18/22.4x 10²³

55.6x6.02x10²³

The value of critical temperature of a gas depends upon its:

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Size

Intermolecular forces in it

Shape

All of above