Tag: general introduction: importance and scope of chemistry

Questions Related to general introduction: importance and scope of chemistry

Atomic radius is expressed in the _______ 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. angstrom

  2. cm

  3. m

  4. nm

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Correct Option: A
Explanation:

Atomic radius is usually expressed in Angstrom units. It is because the size of atom is very small. It is equivalent to $1\times {10}^{-10}$metres.

Weight of diamonds are measured in________.

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

  1. aunce

  2. Kg

  3. carats

  4. pounds

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Correct Option: C
Explanation:

One carat is equal to exactly $0.2$ grams.

The word 'carat' came from the "carob" seed, which was used by diamond traders as the original unit.

If $T _1$ and $T _2$ are two temperatures, which of the following expressions will yield the same value whether both temperatures are given in Celsius or Kelvin?

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

  1. $T _1+T _2$

  2. $T _1-T _2$

  3. $T _1\times T _2$

  4. $\dfrac{T _1}{T _2}$

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Correct Option: B

Which of the following has the highest numeric 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. $100$ Tm

  2. $1000$ Gm

  3. $10^4$ mm

  4. $10^6$ nm

Show answer
Correct Option: A
Explanation:

$100\ Tm=100000\ Gm$

$1000\ Gm$
$10^4\ mm=1\times10^{-10}\ Gm$
$10^6\ nm=1\times10^{-12}\ Gm$

Which of the following is the correct value of $R$ in $SI$ 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. $0.083$ $bar$ $dm^{3}K^{-1}mol^{-1}$

  2. $1.98\ cal K^{-1}mol^{-1}$

  3. $8.314\times 10^{7} erg K^{-1}mol^{-1}$

  4. $8.314 J\ K^{-1}mol^{-1}$

Show answer
Correct Option: D
Explanation:

$R$ is called as universal gas constant or molar gas constant.

              $R=0.0821\quad L\quad atm\quad { mol }^{ -1 }{ k }^{ -1 }\ R=0.0831\quad { dm }^{ 3 }bar\quad { mol }^{ -1 }{ k }^{ -1 }\ R=8.314\quad J\quad { mol }^{ -1 }{ k }^{ -1 }\ R=8.314\times { 10 }^{ 7 }erg\quad { mol }^{ -1 }{ k }^{ -1 }\ R=1.98\quad Cal\quad { mol }^{ -1 }{ k }^{ -1 }$
The $S.I$ units of molar gas constant $(R)$ is $J\quad { mol }^{ -1 }{ k }^{ -1 }$.
$\therefore \quad R=8.314\quad J\quad { mol }^{ -1 }{ k }^{ -1 }$ is the correct answer.

The prefix zepto stands for:

[Note : unit in m]

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

  1. $10^9$

  2. $10^{-12}$

  3. $10^{-15}$

  4. $10^ {-21}$

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Correct Option: D
Explanation:

Zepto = $10^{-21}m$ .

$1^{\circ}C$ rise in temperature is equal to rise of:

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

  1. ${ 1 }^{ 0 }F$

  2. ${ 9/5 }^{ 0 }F$

  3. ${ 5/9 }^{ 0 }F$

  4. ${ 33 }^{ 0 }F$

Show answer
Correct Option: B
Explanation:

Solution:- (B) $\cfrac{9}{5} ℉$

As we now that,
$F  = \cfrac{9}{5} C + 32$
As the temperature is risen by $1 ℃$-
$C' = C + 1$
Therefore,
$F' = \cfrac{9}{5} \left( C + 1 \right) + 32$
$F' = \cfrac{9}{5}C + \cfrac{9}{5} + 32$
$\Rightarrow F' = \left( \cfrac{9}{5}C + 32 \right) + \cfrac{9}{5}$
$\Rightarrow F' = F + \cfrac{9}{5}$
Hence $1 ℃$ rise in temperature is equal to the rise in $\cfrac{9}{5} ℉$.

The prefix femto stands for :

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

  1. $10^9$

  2. $10^{-12}$

  3. $10^{-15}$

  4. $10^5$

Show answer
Correct Option: C

$1^oC$ rise in temperature is equal to a rise of 

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

  1. $1^oF$

  2. $9/5^oF$

  3. $5/9^oF$

  4. $33^oF$

Show answer
Correct Option: B

$mol.kg^{-1}$ is the unit of :

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

  1. Momentum

  2. Velocity

  3. Pressure

  4. Molality

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Correct Option: D