Question # 1

If the distance between Na⁺ and CI^- ions in sodium chloride crystal is X pm,the length of the edge of the unit cell is

Choose an answer

4X om

X/4 pm

X/2 pm

2X pm

What will be the pH of 1.0 mol dm -3 of H2X, which is only 50% dissociated

Choose an answer

1

0

2

Less than 0

2,4,6-Trinitrophenol is commonly called as

Choose an answer

Phthalic acid

Tartaric acid

Malonic acid

Picric acid

Plaster of Paris is obtained from

Choose an answer

marble

bauxite

gypsum

limestone

Which element differs from rest of elements of its group?

Choose an answer

Ba

Mg

Ca

Be

Which thermometer will have its reading 273 degrees greater than that of thermometer C?

Choose an answer

A

B

B has 273 degrees greater than A

C has greater reading than all other thermometers

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

Choose an answer

Triclinic

Monoclinic

Rhombohedral

Isotropical

London dispersion forces are the only force present among the:

Choose an answer

molecules of water in liquid state

atoms of helium in gaseous state at high temperature

molecules of solid iodine

molecules of hydrogen chloride gas

The change in enthalpy of a system when one mole of the substance is completely burnt in excess of air or oxygen is called

Choose an answer

Heat of reaction

Heat of formation

Heat of atomization

Heat of combustion

At absolute zero the molecules of hydrogen gas will have

Choose an answer

Only translatioral motion

Only vibrational motion

Only rotational motion

All the motion are ceased

A basic buffer solution can be prepared by mixing?

Choose an answer

Weak acid and its salt with strong base

Weak base and its salt with strong acid

Strong acid and its salt with weak base

Strong base and its salt with strong acid

What is the formula of magnesite?

Choose an answer

PbS

MgSO4. 7H2O

MgCO3

CaCO3

Acording to the kinetic theory of gases

Choose an answer

The pressure exerted by a gas is proportional to mean square velocity of the molecules

The pressure exerted by the gas is proportional to the root mean square velocity of the molecules

The root mean square velocity is inversely proportional to the temperature

The mean translational KE of the molecule is directly proportional to the absolute temperature

A molecule which contains two lone pairs and two bond pairs of electrons in valence shell of central atom, geometrical shape of molecules will be

Choose an answer

Tetrahedral

Trigonal pyramidal

Angular

Linear

Which one of the following elements is not an alkali metal?

Choose an answer

Na

Sr

Cs

Rb

Which one the following is not postulated in the kinetic molecular theory of gases

Choose an answer

molecules of all the gases have same size and same mass

molecules are in chaotic motion

all molecular collisions are elastic

the volume of the molecules is negligible

During esterifcation, the alcobol molecule acts as:

Choose an answer

Oxidizing agent

Electrophile

Reducing agent

Nucleophile

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

Choose an answer

bond energy

heat of formation

lattice energy

ionization energy

The B.P of H2O at Murree Hills is

Choose an answer

99.8C

98°C

100C°

89°C

Which of the following equation is for idea gas:

Choose an answer

PV = dRT

PR = nTP

PM = nRT

PV = nRT

Which forms metallic crystals

Choose an answer

Cu

NaCI

SO₂

NH₄CI

One Joule is equivalent to

Choose an answer

4.184 cal.

0.4184cal.

1/2 cal.

1/4.184 cal

The mass of 8.5 dm³of oxygen gas at 0.0821 atm and -1°C is

Choose an answer

100 g

10 g

1 g

0.1 g

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

Choose an answer

Pepsin

Thrombin

Ptyalin

Fumarase

The boiling point of Kr is higher (-152.23°C) than that of helium (-268.6°C) due to

Choose an answer

Kr forms greater number of covalent bonds

greater polarizability of Kr than He

Kr has lowest freezing point

Kr is in liquid state at ordinary temperature

The unit of pressure ______ is commonly used by meteorologists

Choose an answer

mm of Hg

Kilopascal

Millibar

Pound per square inch

In NaCl cyrstal Na⁺ion is surrounded by how many ions of Cl^-

Choose an answer

4

6

8

10

At which oxidation state Cu achieves electronic configuration of Zn+2

Choose an answer

0

+2

+1

+3

Which of the following alkyl halides undergoes SN1 reaction fastest

Choose an answer

Methyl chloride

Isobutyl chlorido

Ethy l chloride

Tertiary butyl chloride

At STP,a container has 1 mole of Ar,2 moles of CO₂,3 moles of O₂ and 4 moles of N₂.Without changing the total pressure if one mole of O₂ is removed,the partial pressure of O₂

Choose an answer

Is changed by about 26%

Is halved

Is unchanged

Change by 33%

The molecular speed Crms of gas is

Choose an answer

Independent of temperature

Proportional to the absolute temperature

Proportional to the square root of absolute temperature

Proportional to the square of absolute temperature

By convention, the standard heat of formation of all elements is assumed to be

Choose an answer

Zero

positive

Negative

Infinity

Which of the following is an example of diffusion?

Choose an answer

Spreading of smell of flowers in garden

Steam condensing on a cold window

Bubbles rising in a beaker of boiling water

All of above

The value of Kc for H2O at 25C° is

Choose an answer

1x10 (-14)mole dm-3

14 mol dm-3

1.86×10(-16) mol dm-3

1.0x10 (-7)moldm-3

For an ideal gas,number of moles per litre in terms of its pressure P,gas constant R and temperature T is

Choose an answer

PT/R

PRT

P/RT

RT/P

Total number of possible chain and positional isomers of butyl alcohol among alcohols are

Choose an answer

Four

Five

Two

Six

Enzymes are

Choose an answer

simple proteins

derived proteins

compound proteins

conjugated proteins

The kinetic energy of three moles of gas is:

Choose an answer

3/2 RT

3 RT

1/2 RT

2 RT

The polarizabilities of elements mostly increase down the group due to the reason that

Choose an answer

the atomic numbers increase

number of protons increase

number of shells increase along with increase of shielding effect

the behaviour of the elements remain the same

As the number of carbon atoms increases the number of isomers also increase. The 5 C compound pentane has as many as

Choose an answer

3 isomers

5 isomers

6 isomers

10 isomers

Ethane when completely halogenated in excess of chiorine can form

Choose an answer

Hexachloroethane

Dichloroethane

Pentachloroethane

1.1.2.2-terachloroethane

Phenol is colourless, crystalline and solid

Choose an answer

Hygroscopie

Deliquescent

Moistening

Odourless

Which of the following enthalpy change always have a negative value

Choose an answer

∆Hf

∆H sol

∆Hc

∆Hat

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

Choose an answer

π/2

2/π

√π/2

The number of unpaired electrons present in Fe ions is

Choose an answer

1

2

5

0

Which of following is oxidation state of oxygen in peroxides?

Choose an answer

-2

1/2

-1

+2

Gases show uniform behavior towards their:

Choose an answer

Internal conditions.

External conditions.

Internal and external conditions.

None of above.

The heat of reaction depends upon

Choose an answer

Temperature of the reactants

Physical states of the reactants and the products

Both A) and B)

Path of the reaction and the temperature

H2O and HF are the hydrides of the second period. Fluorine is more electronegative than oxygen. Anyhow, the boiling point of water is greater than that of HF. This is due to:

Choose an answer

water is more polar than HF

water has a bent structure

HF has a zig zag structure after making hydrogen bonding

the number of hydrogen bonds produced by water are greater than that of HF

What is the reason of ionic solids for not conducting electricity?

Choose an answer

free electrons are less

ions don't have translatory mention.

ions don't have translatory mention

the coordination number of the ion is very high.

The scale of temperature that shows the freezing point of water at 0° is called

Choose an answer

Fahrenheit

Kelvin

absolute

Celsius

Which one of the following is NOT a nucleophile

Choose an answer

NH2+

BF3

H2O

CH3-

Calorie is equivalent to

Choose an answer

0.4184J

4.184J

418.4J

40.18J

The carbon atom of an alkyl group attached with halogen atom is called

Choose an answer

Electrophile

Free redical

Nucleophile

Nucleophilic centre

SiO₂ is an example of:

Choose an answer

metallic crystals

lonic crystals

a crystal whose structure depending upon the temperature

covalent crystals

Which one of the following has the lowest pH values

Choose an answer

0.1 M HCI

0.01 M HCl

0.1 M KOH

0.01 M KOH

The temperature of a gas is directly proportional to its

Choose an answer

average translational kinetic energy

enthalpy

internal energy

hydration energy

In Boyle's law which of the following pair remains constant:

Choose an answer

Temperature and quality of a gas.

Pressure and quality of a gas.

Temperature and pressure.

Temperature and quantity of a gas.

The height of the peak in the mass spectrum shows

Choose an answer

Number of isotopes

Relative abundance

Mass number

Number of protons

A molecule that has polar bonds but is overall non - polar

Choose an answer

IF

CCl4

PCI3

All

The actual volume of gas molecules is considered negligible at following pressures

Choose an answer

2atm

4atm

6 atm

8 atm