Some Basic Concepts of Chemistry Test

Result

Some Basic Concepts of Chemistry Test - 5

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

Chemistry does not play a major role in

A
Explaining superconductivity

B
Explaining ozone depletion

C
Large scale production of a variety of fertilizers

D
Design and synthesis new materials having specific magnetic, electric and optical properties.

Solution

Chemistry does not deal in explaining superconductivity.

*In superconducting materials the charecteristics of superconductivity appear when the temperature is lowered below a critical temperature.

*The onset of superconductivity is accompanied by abrupt changes in physical properties which are more related to phase transitions of the material .

These aspects of studies in properties of materials are better related to studies in the fields of Physics , eventhough principles involved in Chemistry & Physics go hand to hand.
Question 2
1 / -0

Matter can be classified at the macroscopic or bulk level as

A
Elements and molecules

B
solids and liquids

C
Atoms and molecules

D
mixtures or pure substances

Solution

At macroscopic level matter is classified as mixture or pure substances

.A mixture contains two or more components (in any ratio ) present in it , for example -- sugar solutions in water , tea , air , alloys like brass ,bronze etc.

Pure substances (viz. copper , silver , gold , water , glucose etc . ) have fixed composition .

The constituents of pure substances can not be separated by simple physical methods.
Question 3
1 / -0

In a homogeneous mixture,the components are

A
completely mix with each other and its composition is not uniform throughout

B
completely mixed with each other and its composition is uniform through out

C
do not mix with each other and its composition is not uniform throughout

D
do not mix with each other and its composition is uniform throughout.

Solution

In a homogeneous mixture ,

(i) the components are mixed together completely ,

(ii) has a uniform composition throughout.
Question 4
1 / -0

Which of the following statements about pure substances is correct ?

A
Pure substances are compounds only

B
Pure substances are elements only.

C
Pure substances have fixed composition.

D
Pure substances do not have fixed composition .

Solution

Pure substances have fixed composition..These may be both (ie. either elements or compounds ) . The law of constant composition holds good for such substances .
Question 5
1 / -0

Particles of compounds are

A
atoms

B
heterogeneous mixtures .

C
homogeneous mixtures .

D
molecules of two or more atoms of different elements

Solution

Compounds are made when,

atoms of two or more different elements combine together in fixed ratio to form molecules .(viz. water , ammonia , carbon- di- oxide glucose etc. ) .

Thus the particles of compound consists of molecules.
Question 6
1 / -0

Fill up the blank with suitable word in the statement,

" Physical properties are those properties which are measured or observed--------------- changing the identity or the composition of the substance ."

A
with

B
without

C
by

D
after

Solution

A substance is identified by its composition , hence for measuring physical properties of a substance its identity must be retained , (or should not be changed ) Hence , the given statement ,

" Physical properties are those properties which are measured or observed without changing the identity or composition of the substance."

is correct.
Question 7
1 / -0

SI units for Base Physical Quantities of length, mass and current are

A
decimetre, kilogram, ampere

B
meter, gram, ampere

C
meter, kilogram, candela

D
meter, kilogram, ampere

Solution

The International System of units ( abbreviated as SI ) is modern form of metric system , and is most widely used form of measurements .

It comprises of a coherent system of measurement built of seven base units .

The base units for length , mass and current in this system of measurements are , " meter , kilogram , ampere " ,symbolised respectively as as

m ,kg , A
Question 8
1 / -0

SI unit of density is

A
kg m³

B
kg m⁻²

C
kg⁻¹m³

D
kg m⁻³

Solution

Since, density

= mass / volume ;

and  SI unit of mass is kg and that of volume is m3m3

∴∴ using these SI units the unit of density is derived through dimensional analysis :

density  = mass / volume

= kg / m³

or, =  kg m^-³
Question 9
1 / -0

The kelvin scale is related to celsius scale as :

A
K = °C + 100

B
K = °C + 32

C
K = °C + 273.15

D
K = °C + 212

Solution

The relation between Kelvin scale & Celcius scale of temperatures is -

K = °C + 273.15

Such a relation is based upon the experimental findings and subsequent conclusion of Charle's law .

The Kelvin scale is also termed as " absolute scale of temperature."

It is interesting to note that temperature below 0^o C ( ie. negative values ) are possible in Celcius scale but in Kelvin scale , negative temperature is not possible .
Question 10
1 / -0

In scientific notation for numbers, any number can be represented in the form ,

N × 10ⁿ where,

A
n is an exponent having positive or negative values and N can vary from 10 to 100

B
n is an exponent having positive or negative values . N represents a number which can vary from 1 to 10 , but not 10 itself .

C
n is an exponent having positive or negative values and N can vary from 0 to 1

D
n is an exponent having positive values only and N can vary from 1 to 10

Solution

Scientific notation is conveniently used to represent extremely large or even very small numerical values . It is an exponential notation in which any number can be represented in the form , N x 10ⁿ , where n is an exponent having positive or negative values and N can vary between 1 and 10 , but not 10 itself.

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

Some Basic Concepts of Chemistry Test - 5

Result

Some Basic Concepts of Chemistry Test - 5

Score

-

Rank

-

SHARING IS CARING

Question 1

Explaining superconductivity

Explaining ozone depletion

Large scale production of a variety of fertilizers

Design and synthesis new materials having specific magnetic, electric and optical properties.

Solution

Question 2

Elements and molecules

solids and liquids

Atoms and molecules

mixtures or pure substances

Solution

Question 3

completely mix with each other and its composition is not uniform throughout

completely mixed with each other and its composition is uniform through out

do not mix with each other and its composition is not uniform throughout

do not mix with each other and its composition is uniform throughout.

Solution

Question 4

Pure substances are compounds only

Pure substances are elements only.

Pure substances have fixed composition.

Pure substances do not have fixed composition .

Solution

Question 5

atoms

heterogeneous mixtures .

homogeneous mixtures .

molecules of two or more atoms of different elements

Solution

Question 6

with

without

by

after

Solution

Question 7

decimetre, kilogram, ampere

meter, gram, ampere

meter, kilogram, candela

meter, kilogram, ampere

Solution

Question 8

kg m3

kg m−2

kg−1m3

kg m−3

Solution

Question 9

K = °C + 100

K = °C + 32

K = °C + 273.15

K = °C + 212

Solution

Question 10

n is an exponent having positive or negative values and N can vary from 10 to 100

n is an exponent having positive or negative values . N represents a number which can vary from 1 to 10 , but not 10 itself .

n is an exponent having positive or negative values and N can vary from 0 to 1

n is an exponent having positive values only and N can vary from 1 to 10

Solution

User

Question Analysis

My Perfomance

Score

-

Rank

-

Results Announcement on: coming Monday

Stay Tuned: We’ll update you on your result via email or SMS.

kg m³

kg m⁻²

kg⁻¹m³

kg m⁻³