Tag: matter around us

Questions Related to matter around us

Kelvin scale has:

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

  1. no fixed points

  2. one fixed point.

  3. two fixed points

  4. none of these

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Correct Option: C
Explanation:

In Kelvin scale, temperature is expressed in Kelvin. In SI system, Kelvin is the unit of temperature. In this scale of temperature, zero of the scale corresponds to $-273^0C$, which is said to be the temperature at which the volume of a gas reduces to zero. Hence, $-273^0C$ is also known as the absolute zero. For the same reason, this scale of temperature is also known as absolute scale of temperature. On this scale, the lower fixed point i.e. the temperature of melting ice at normal pressure is +273K and the upper fixed point i.e. the temperature of boiling water at normal pressure is 373K. 

Which of the following are incorrect SI units?

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

  1. Amount of substance in mol L$^{-1}$

  2. Pressure of gas in pascal

  3. Density of a solid in kg m$^{-3}$

  4. Force in newton

Show answer
Correct Option: A
Explanation:

The SI units is based on seven base units. These are metre, kilogram, second, ampere, kelvin, mole and candela.

Here Pascal is SI unit of pressure
Newton is unit of force

Amount of substance has a SI unit $mol/ m^3$
Option A is the incorrect SI Unit.

One gram of mass is equal to:

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

  1. $5\times { 10 }^{ 10 }erg$

  2. $9\times { 10 }^{ 20 }erg$

  3. $7\times { 10 }^{ 5 }erg$

  4. $11\times { 10 }^{ 12 }erg$

Show answer
Correct Option: B
Explanation:

$E=mc^2$

$E=1\ g \times (3\times 10^{10}\ cm/s)^2 $
$=9\times 10^{20}\ erg$

Which of the following relationships are 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. $1 \,atm\approx 0.1 \, bar$

  2. $1 \,liter= 1 \, dm^3$

  3. $1\, J =0.239 \, cal$

  4. $1\, eV =9.11 \times 10^{-4} J$

Show answer
Correct Option: A,D
Explanation:

$1\quad atm=1.01325\quad bar\approx 1\quad bar\neq 0.1\quad bar$

$1\quad litre={ 10 }^{ -3 }{ m }^{ 3 }=1{ dm }^{ 3 }$
$1\quad cal =4.18\quad J \Rightarrow 1\quad J =0.239\quad cal\ 1\quad ev=1.6\times { 10 }^{ -19 }J \neq  9.11\times { 10 }^{ -4 }J$
Therefore, $(A). (D)$ are the correct answer.

Units of physical quantities can be expressed in terms of fundamental units and such units are called:

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

  1. Fundamental units

  2. Derived units

  3. Both a and b

  4. None of the above

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Correct Option: B
Explanation:

Units of physical quantities can be expressed in terms of fundamental units and such units are called $\text{derived units}$. 

Unit of area can be an example for derived unit. If $L$ is the length of the square then $L \times L$ is $L^{2}$ is its area. Hence, option A is correct.

The units of fundamental physical quantities are called

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

  1. Fundamental units

  2. Derived units

  3. Both a and b

  4. None of the above

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Correct Option: A
Explanation:

The units of fundamental physical quantities are called fundamental units. They are length, mass and time.
Hence option A is correct.

Match the following combinations of electrical units with their terms as single unit:

Electrical unit Single unit
(I) ampere-second A. coulomb
(II) volt-ampere B. ohm
(III) volt-ampere$^{-1}$ C. ampere
(IV) walt/ampere ohm D. watt
(V) joule / ampere second E. volt
chemistry matter around us measurement of properties effect of temperature and pressure on states of matter general introduction: importance and scope of chemistry

  1. A- I B-III C-IV D-II E-V

  2. A- I B-II C-III D-IV E-V

  3. A- V B-IV C-III D-II E-I

  4. A- I B-V C-IV D-II E-III

Show answer
Correct Option: A
Explanation:

Electrical unit     Single unit

(I) ampere-second                   coulomb

(II) volt-ampere                         Ampere

(III) volt-ampere$^{-1}$         Volt

(IV) walt/ampere ohm              Ohm

(V) joule / ampere second       Volt

So correct options are A- I B-III C-IV D-II E-V

Hence option A is correct.

Which of the following is the non- derived unit?

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

  1. Time

  2. Mass

  3. Length

  4. All of the above

Show answer
Correct Option: D
Explanation:

Non-derived units or fundamental units are the units which are used to derive other units. The fundamental units are length, mass, temperature, time, electric current, liminous & mole.

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. Time

  3. Density

  4. Amount of substance

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Correct Option: C
Explanation:

Basic physical quantities are those that are physical fundamental units. There are seven basic fundamental quantities: Length, mass, time, electric current, amount of substance, luminous intensity & temperature. The quantities which are derived with the help of these basic physical quantities are called derived quantities. They are density, volume, pressure, force, etc.

What should be the volume of the milk (in $m^3$) which measures 5 L?

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

  1. $5 \times 10^{-3} m^{3}$

  2. $5 \times 10^{3} m^{3}$

  3. $5 \times 1000 \ m^{3}$

  4. $5 \times 10^{6} m^{3}$

Show answer
Correct Option: A
Explanation:
$1\ L=10^{-3}\ m^{3}$
Since 1 L = 1000 $cm^3$ and 1 m = 100 cm
$\dfrac {1 m}{100 cm} = 1 = \dfrac{100 cm}{1 m}, or (\dfrac {1 m}{100 cm})^3 = \dfrac{1m^3}{10^6cm^3}$ = $1^3$ = 1

Therefore $5\ L=5 \times 10^{-3}\ m^{3}$
option A is correct