Tag: general introduction: importance and scope of chemistry

Questions Related to general introduction: importance and scope of chemistry

What is the physical state of water at $30^{\circ} C$?

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

  1. Solid

  2. Liquid

  3. Gas

  4. None of the above

Show answer
Correct Option: B
Explanation:

Water at $30^{\circ}C$ is liquid and it remains in liquid state from $0^{\circ}C$ to $100^{\circ}C$.

Convert $-273^oC$ to Kelvin scale.

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 K

  2. 273 K

  3. 300 K

  4. 5 K

Show answer
Correct Option: A
Explanation:

To convert from the Celsius scale to the Kelvin scale, we add $273$ to the Celsius scale. So, $-273+273=0\ K$


Hence, the correct option is $A$

The S.I. unit of length 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. metre

  2. kilometre

  3. foot

  4. yard

Show answer
Correct Option: A
Explanation:

The S.I. unit of length is metre.

The atmospheric pressure at sea level 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. 1 atm

  2. 10 atm

  3. 100 atm

  4. 1 pascal

Show answer
Correct Option: A
Explanation:

The atmospheric pressure at sea level is 1 atm.

Convert $100^oC$ to 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. $273$

  2. $373$

  3. $473$

  4. $573$

Show answer
Correct Option: B
Explanation:

The formula for conversion of centigrade unit to kelvin is :


$T(K)= T(^oC) + 273$


 $T(K)=100+273$

$=373K$

Option (B) is correct.

What is the physical state of water at $125^{\circ} C$?

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

  1. Solid

  2. Liquid

  3. Gas

  4. None of the above

Show answer
Correct Option: C
Explanation:

Water boils at $100^{\circ}C$ and it converts into vapour above this temperature.

To convert Kelvin scale to Celsius scale:

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

  1. add $273$ to Kelvin scale

  2. subtract $273$ from Kelvin scale

  3. multiply $273$ with Kelvin scale

  4. divide $273$ by Kelvin scale

Show answer
Correct Option: B
Explanation:
$^0C=K-273$
To convert Kelvin to Celsius, subtract $273$ from kelvin scale.

Hence, option $B$ is the answer.

The S.I. unit of weight 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. kilogram

  2. gram

  3. newton

  4. milligram

Show answer
Correct Option: C
Explanation:

The S.I. unit of weight is newton since weight is the reaction force of an object due to gravity. 

To convert Celsius scale to Kelvin scale:

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

  1. add $273$ to Celsius scale

  2. subtract $273$ from Celsius scale

  3. multiply $273$ with Celsius scale

  4. divide $273$ by Celsius scale

Show answer
Correct Option: A
Explanation:

To convert from Celsius scale to Kelvin scale, add 273 to Celsius scale.

What is the density of a metal which has a mass of $15g$ and a volume of $2mL$?

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

  1. $7.5$

  2. $17$

  3. $0.15$

  4. $13$

  5. $30$

Show answer
Correct Option: A
Explanation:

$Density= \cfrac {mass}{volume}= \cfrac {15g}{2ml}= 7.5\quad g/ml$