Question # 1

Equal volumes of gases at the same temperature and pressure contain equal number of particles.This statement is direct consequence of

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Perfect gas law

Partial law of volumes

Charle's law

Ideal gas equation

To distinguish aldehyde from ketone which solution is used

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Alkaline solution

Fehling's solution

A solution containing K2Cr2O7

A solution containing acid only

In a group, the atomic radii from top to bottom

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increase

decrease

don't change

show variable trend

All of the following have cleavage planes except:

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molecular crystals

metallic crystals

covanent crystals

ionic crystals

Succinic thiokinase is an enzyme of the type

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mutase

peroxidase

ligase

lyase

Temperature required for the dehydration of ethanol into ethene in the presence of HaSOu is

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130°C

170°C

175°C

180°C

Which of the substance is not going to react the sodium metal:

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Acetic acid

Methanol

Di methyl ether

Ethanol

Absolute zero is equal to:

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-273.15K

-273.15^oC

-237.15K

-273 ^oC

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

How should the conditions be changed to prevent the volume of a given gas from expanding when its mass increased?

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temperature and pressure both ara increased

temperature and pressure both are lowered

temperature is lowered and pressure is increased

temperature is increased and pressure is descreased

The value of Kc for H2O at 25C° is

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1x10 (-14)mole dm-3

14 mol dm-3

1.86×10(-16) mol dm-3

1.0x10 (-7)moldm-3

Equal masses of methane and oxygen are mixed in an empty container at 25∘C.

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1/3

8/9

1/9

16/17

Absolute temperature is the temperature at which

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All molecular motion ceases

volume becomes zero

Mass becomes zero

None of these

What will be the pH of 1.0 mol dm-3 of NH4OH, which is 1% dissociated

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2

12

0

2.7

Some of crystals are good conductors of heat and electricity, they may be

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ionic in nature

of metallic character

covalent in nature

of molecular nature

The stoichiometric calculations for a chemical reaction results in

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Actual yield

Percentage yield

Theoretical yield

Selectivity

.Both aldehydes and ketones are planar to the neighborhoods of carbonyl (C-0) group. Which one of the following bonds is distorted towards the oxygen atoms?

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pi-bond of C and O

Sigma bond of C and O

Sigma bond of C and H

Sigma bond of C and C

For which mechanisms, the first step involved is the same

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E1 and E2

E2 and SN2

E2 and E1

E1 and SN1

Which is trigonal cyrstal

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BaSO₄. 4H₂O

FeSO₄

NaNO₃

None

H₂O is liquid at room temperature whereas H₂S is a gas because

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H₂O used as drinking water, but H₂S has rotten egg smell

H₂O is neutral. H₂S is a weak acid

stronger hydrogen bonding in H₂O than in H₂S

H₂O occurs abundantly than H₂S

The specie that develops strongest hydrogen bonding with water

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НСООН

B.CH3CH2СООН

CH3СООН

CICH2COOH

One of the best applications of Hess's law to calculate the lattice energy of ionic compound is

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Measurement of enthalpy change in a calorimeter

Studying of first law of thermodynamics

Measurement of a heat of formation of a compound

Born-Haber cycle

Mass spectrometry is used to determine the

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Number of isotopes of an element

Relative abundance of isotopes

Relative isotopic masses

All of these

The amount of energy released when gaseous ions of opposite charges combine to give one mole of a crystalline ionic compound is called

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bond energy

heat of formation

lattice energy

ionization energy

A real gas obeying Vander Waal's equation will resemble ideal gas if

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Both a and b are large

Both a and b are small

a is small and b is large

a is large and b is small

Coinage metals Cu. Ag, and Au are the least reactive because they have

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Negative reduction potential

Positive reduction potential

Negative oxidation potential

Positive oxidation potential

London forces are

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stronger than dipole-dipole interactions

weaker than dipole-dipole interactions

equal to dipole-dipole interactions

sometimes stronger and sometimes weaker than dipole-dipole interactions

A solid has a sharp melting point slightly above room temperature and is a poor thermal and electrical conductor, its crystal classification by bond type is

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Ionic

Metallic

Molecular

Covalent

In the esterification, first attack is due toon carborylic acid

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Hydrogen ion

Alcohols

Water

All

Which of the following solids has a simple molecular lattice?

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magnesium oxide

sodium

silicon(IV) oxide

sulphur

In the equation PV = nRT which one cannot be numerically equal to R

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8.31 x 10⁷ erg⁷ K^-1 mol^-1

8.31 x 10⁷ dynes Cm K^-1 mol^-1

8.31 JK^-1 mol^-1

8.31 L atm K^-1 mol^-1

Hardness of diamond is attributed to the

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strength of the ionic bonds in the structure

three-dimensional network of covalent bonds

absence of valence electrons in carbon atoms

The distribution of energies among the molecules of gases was studied by:

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Maxwell

Coulomb

Newton

Boltzmann

Saturated hydrocarbons having carbon atoms more than 20 in a molecule are solids due to

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higher densities

higher molar masses

the chain, are more zig-zag

all are correct

When wine is put in air, it becomes sour due to

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Oxidation of C2H5OH

Formation of C2H5NH2

Reduction of C2H5OH

Dissolution of CO2

Sugar crystals belong to the system

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cubic

monoclinic

triclinic

orthorhombic

General gas equation is combination of

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Boyle s law

Avogadro s law

Charles s law

All of these

Which one is a non-polar compound?

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SnCl2

PH3

Gecl4

H2O

The value of ∆V being very small. The term P∆V can be neglected for process involving

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Liquid and gas

Solids and gases

Liquid and solid

None of these

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

The compound that has zero dipole moment is

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HCl

H₂S

NH₃

CH₄

Formamide is formed by the reaction of which acid with ammonia

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Oualic acid

Formic acid

Ethanoic acid

Propanoic acid

Lonic solids are characterized by:

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low melting points

_{good conductivety in solid state}

high vapour pressures

solubility in polar solvents

The protein component of enzyme ls called

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apoenzyme

proenzyme

holoenyme

co-enzyme

Which of the following is not a property of enzymes?

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extraordinary speciffcity

reversibility of reactions

high efficiency

minimum activity at optimum T

Glyoxal molecule has?

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two carbonyl groups

One aldehydic and one carbonyl group

Two aldehydic groups

Two carboxyl group

The height of the peak in the mass spectrum shows

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Number of isotopes

Relative abundance

Mass number

Number of protons

The rate of diffusion of two gases are inverselly proportional to the square roots of their densities or molecular weights, is a statement of

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Charle's Law

Boyle's Law

Graham's Law

Dalton's Law

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

Coinage metals Cu, Ag and Au are the least reactive because they have

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Negative reduction potential

Negative oxidation potential

Positive reduction potential

Positive oxidation potential

The graph between pressure and volume at constant temperature for gas is:

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Isobaric

Isothermal

Isotherm

None of above

The value of the vapour pressure of water at its boiling point at Karachi and Murree is

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same

different

depends upon the environmental conditions in both cities

greater at Murree and less at Karachi

Pressure remain constant at which temperature the volume of gas becomes twice of what it is at 0°C

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546 °C

546K

200°C

273K

If V₁= 5 litres, P₁= 2 atm, T₁= T₂= 273°C and V₂= in liter

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5

80

125

10

NH₃shows maximum boiling among the hydrides of group V elements. The is due to:

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pyramidal structure of NH₃

H-bonding between its molecules

enhanced electronegative character

very small size of nitrogen

The Kw. of water at 25 C° is given by

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10(-7)

10(-10)

10(-12)

10(-14)

Increased concentration of enzyme alkaline phosphatase is a sign of

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hemophilia

heart disease

thrombosis

rickets

which of the following is not a symmetrical ketone

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4-heptanone

Butanone

Propanone

3-pentanone

In which one of the following does the central atom not possess an 'octet' in its outer shell?

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BH₃

CH₄

NH₃

H₂O

Which isomer of C4H9Br will produce 2-methyl propane-2-ol on treatment with aqueous KOH

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n-butyI bromide

Sec-butyI bromide

Isobutyl halide

Tertiary butyl chloride

Liquid hydrocarbon is

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methane

propane

ethane

hexane