Tag: matter around us

Quizzes (25) Questions (106)

Questions Related to matter around us

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

Which of the following is the correct value of $R$ in $SI$ units?

  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. $8.314 J\ K^{-1}mol^{-1}$
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

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

  1. ${ 1 }^{ 0 }F$
  2. ${ 9/5 }^{ 0 }F$
  3. ${ 5/9 }^{ 0 }F$
  4. ${ 33 }^{ 0 }F$
Reveal answer Fill a bubble to check yourself
B Correct answer
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 $\cfrac{9}{5} ℉$.

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

If the temperature of a water bath is $104^{0}\ F$ then its value in degree Celsius scale will be?

  1. $35^{0}C$
  2. $45^{0}C$
  3. $50^{0}C$
  4. $40^{0}C$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Conversion from Fahrenheit to Celsius



$(T\ °F − 32) \times \dfrac{5}{9} = t\ °C$

Substituting it, we get,

$(104\ °F − 32) \times \dfrac{5}{9} = 40\ °C$


Hence, the correct option is $D$

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

Thermometer $(A) & (B)$ have ice points marked at $15^oC & 25^oC$ and steam points at $75^oC & 125^oC$ respectively. When thermometer A measures the temperrature of a bath as $60^oC$ the reading of B for the same bath is :-

  1. $60^oC$
  2. $75^oC$
  3. $90^oC$
  4. $100^oC$
Reveal answer Fill a bubble to check yourself
B Correct answer
Multiple choice chemistry matter around us measurement of properties effect of temperature and pressure on states of matter general introduction: importance and scope of chemistry

Weight of a body is:

  1. constant

  2. not constant

  3. does not change from place to place

  4. both A and C
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Mass of a body is constant whereas weight of a body depends on the acceleration due to gravity at that point. Therefore, weight of body is not constant & varies from place to place.