Gaseous State

Step 1: Convert temperature into Kelvin.


Step 2: Apply Charles’ law.
At constant pressure:

Step 3: Substitute given values.


Step 4: Solve for .


Step 5: Conclusion.
The volume of the gas at is .

Step 1: Recall absolute zero.
Absolute zero is the lowest theoretical temperature at which the volume of an ideal gas becomes zero.
Step 2: Relate Celsius and Kelvin scales.
Absolute zero corresponds to , which is equal to .
Step 3: Conclusion.
Therefore, the volume of a gas becomes absolutely zero at .

Step 1: Understanding addition polymers.
Addition polymers are formed by the repeated addition of monomer units without the elimination of any small molecules.

Step 2: Analyzing the options.
Dacron, urea-formaldehyde polymer, and Nylon-6 are formed by condensation polymerization with elimination of small molecules.

Step 3: Identifying polythene.
Polythene is formed by the addition polymerization of ethene molecules without loss of any by-product.

Step 4: Conclusion.
Thus, polythene is an example of an addition polymer.

Step 1: Understanding the relationship.
According to Charles' law, for a fixed mass of gas at constant pressure, the volume of the gas is directly proportional to the temperature (in Kelvin). This can be written as: Where and are the initial volume and temperature, and and are the final volume and temperature.
Step 2: Applying the values.
Given that the initial temperature is K, the initial volume is 2 dm , and the final temperature is K, we can calculate the final volume : Solving for : Step 3: Conclusion.
The correct answer is (A) 20 dm . The volume increases by a factor of 10 when the temperature increases from K to K.

Step 1: Understanding Andrews Isotherms.
Andrews isotherms provide information about the behavior of gases at different pressures and temperatures. For carbon dioxide, the temperature at which it begins to condense into a liquid at a pressure of 73 atm is a critical value known from experimental data. This value corresponds to the temperature 30.98 C.

Step 2: Analyzing the options.
(A) 21.5 C: Incorrect. This temperature is lower than the condensation temperature at 73 atm.
(B) 30.98 C: Correct. This is the correct temperature at which CO starts to condense at 73 atm, as observed from the isothermal curves for CO .
(C) 13.1 C: Incorrect. This temperature is much lower than the actual condensation point at 73 atm.
(D) 48.1 C: Incorrect. This is too high a temperature for the condensation of CO at 73 atm.

Step 3: Conclusion.
The correct temperature at which carbon dioxide starts to condense at 73 atm is 30.98 C, corresponding to option (B).

Step 1: Relation between moles and number of molecules.
The number of molecules present in a gas sample is directly proportional to the number of moles present.

Step 2: Calculation of moles for each option.

Step 3: Comparison.
The sample containing the highest number of moles will have the maximum number of molecules. Here, g of has the highest number of moles.

Step 4: Conclusion.
Therefore, the gas sample with the maximum number of molecules is g of }.