Tag: general introduction: importance and scope of chemistry

Questions Related to general introduction: importance and scope of chemistry

The prefix of $10^{18}$ is:

chemistry matter around us measurement of properties effect of temperature and pressure on states of matter general introduction: importance and scope of chemistry

  1. giga

  2. exa

  3. kilo

  4. nano

  5. mega

Show answer
Correct Option: B
Explanation:

The prefix of ${ 10 }^{ 3 }=$ kilo

                       ${ 10 }^{ 6 }=$ mega
                       ${ 10 }^{ 9 }=$ giga
                       ${ 10 }^{ 18 }=$ exa
Therefore, the prefix of ${ 10 }^{ 18 }$ is exa

SI unit of energy is: 

chemistry matter around us measurement of properties effect of temperature and pressure on states of matter general introduction: importance and scope of chemistry

  1. $kg\, m^2 s^{-2}$

  2. $kg\, m^{-1} s^{2}$

  3. $kg\, m^2 s^{-1}$

  4. $kg\, m^2 s^{2}$

Show answer
Correct Option: A
Explanation:

The power required to do work by the application of force is energy.

Energy has same unit as that of work.
$\therefore$ S.I unit of Energy is $kgm^2 s^{-2}$

Which of the following is the correct unit for measuring nuclear radii?

chemistry matter around us measurement of properties effect of temperature and pressure on states of matter general introduction: importance and scope of chemistry

  1. Micron

  2. Millimetre

  3. Angstrom

  4. Fermi

Show answer
Correct Option: D
Explanation:

$\text{Nuclear radii are measured in Fermi ie. }$$10^{-15}$

$298 K$ is what temperature in Fahrenheit?

chemistry matter around us measurement of properties effect of temperature and pressure on states of matter general introduction: importance and scope of chemistry

  1. $76.73F$

  2. $80F$

  3. $75F$

  4. $27F$

Show answer
Correct Option: A
Explanation:

${ T } _{ K }={ (T } _{ F }+459.67)\times \frac { 5 }{ 9 } \ \Rightarrow 298={ (T } _{ F }+459.67)\times \frac { 5 }{ 9 } \ \Rightarrow \frac { 298\times 9 }{ 5 } -459.67={ T } _{ F }\ \Rightarrow { T } _{ F }=536.4-459.67={ 76.73 }^{ 0 }F$

The amount of heat energy released when a fuel burns completely is called calorific value.

chemistry matter around us measurement of properties effect of temperature and pressure on states of matter general introduction: importance and scope of chemistry

  1. True

  2. False

  3. Nither

  4. Either

Show answer
Correct Option: B
Explanation:
$\text{Calorific value= heat released per kg of fule}$

$\text{The amount of heat energy released when a one kilogram of fuel burns completely is called calorific value.}$

Which of the following is not a basic physical quantity?

chemistry matter around us measurement of properties effect of temperature and pressure on states of matter general introduction: importance and scope of chemistry

  1. Length

  2. Force

  3. Time

  4. Amount of substance

Show answer
Correct Option: B
Explanation:

The physical property of a body, substance or phenomenon that can be quantified by measurement is defined as a physical quantity.

There are seven fundamental physical quantities viz. time, length, mass, amount of substance, luminous intensity, temperature, and electric current.
Here force is a derived unit.
Thus the correct answer is force.

The commercial unit of electrical energy is :
chemistry matter around us measurement of properties effect of temperature and pressure on states of matter general introduction: importance and scope of chemistry

  1. Watt

  2. Kilo Watt hour

  3. Watt/ hour

  4. Ohm

Show answer
Correct Option: B
Explanation:

The kilowatt-hour is commonly used as a billing unit for energy delivered to consumers by electric utilities.

Energy spent in kilowatt-hour $=\cfrac {volt \times...........\times......}{1000}$.

chemistry matter around us measurement of properties effect of temperature and pressure on states of matter general introduction: importance and scope of chemistry

  1. ampere, hour

  2. ohm,min

  3. ampere,min

  4. joule,hour

Show answer
Correct Option: A
Explanation:

Energy = Work done $(in\ Watt) =  Power\times time = Voltage \times current \times time$


$Work\ done\ (in\ kilowatt) = \dfrac{(Voltage\times current\times time)}{ 1000}$

$Or\ work\ done\ (in\ kilowatt) = \dfrac{(Volt\times ampere\times hour)}{ 1000}$

Which of the following is wrong?

chemistry matter around us measurement of properties effect of temperature and pressure on states of matter general introduction: importance and scope of chemistry

  1. 1 inch = 2.54 cm

  2. 1 foot = 3.305 m

  3. 1 mile = 1.609 km

  4. 1 lb. = 453.59 gm

Show answer
Correct Option: B
Explanation:

Answer is option $B$. 

Since $1$ $foot=0.3048m$

Mark the conversion factor which is not correct.

chemistry matter around us measurement of properties effect of temperature and pressure on states of matter general introduction: importance and scope of chemistry

  1. 1 atm $= 1.01325 \times 10^5 \ Pa$

  2. 1 metre $= 39.37\ inch$

  3. 1 litre $= 10^{-3}\ m^3$

  4. 1 inch $= 3.33\ cm$

Show answer
Correct Option: D
Explanation:

A. 1 atm = $1.01325 \times 10^5\ Pa$

B. 1 metre = $39.37\ inches$
C. 1 litre = $10^{−3}\ m^3$
D. 1 inch = $2.54\ cm$
option D is correct