States Of Matter

Step 1: Root mean square (rms) velocity of a gas is given by:
Step 2: From the formula:
Step 3: If rms velocity is tripled:
Step 4: Squaring both sides:
Step 5: Hence, temperature must be increased by nine times.

Step 1: Ideal gas behaviour assumes:
Negligible intermolecular forces
Negligible volume of gas molecules
Step 2: At high temperature, kinetic energy of gas molecules is very large, so the effect of intermolecular attractions becomes negligible.
Step 3: At low pressure, gas molecules are far apart, so their own volume and intermolecular forces can be ignored.
Step 4: Therefore, under conditions of high temperature and low pressure, a real gas behaves most like an ideal gas.

Step 1: At STP, of any gas corresponds to 1 mole.
Step 2: Molar mass of
Step 3: Molar mass of Methane
Step 4: Volume of Methane at STP:
Step 5: Since mass comparison questions at STP are generally based on the relation: the closest correct option provided is:

Step 1: Vapour density 20 ⇒ molar mass of mixture
Step 2: Let moles of CO = , moles of CO = . Total moles:
Step 3: Mass equation using molar masses ( , }}=44\) )
Step 4: From (1), . Substitute in (2): Hence the mixture contains 0.625 mole of CO.

Step 1: Constant temperature ⇒ internal kinetic energy remains unchanged.
Step 2: During expansion at same T - molecules do not increase → (B wrong), - pressure falls rather than increases → (D wrong).
Step 3: The only universally true statement is kinetic energy remains same. Hence the incorrect choice asked in options identification is (C).

Step 1: Given concentration of NaOH After dilution by 100 times: Step 2: Consider contribution of water. Pure water contributes: Total hydroxide ion concentration: Step 3: Calculate pOH: Step 4: Calculate pH: Since the pH is slightly greater than 7, it lies between 7 and 8.

The initial concentration of is .
After 100 times dilution, the from the base is:
.
Since this concentration is comparable to from water auto-ionization ( ), the total must be considered.
Total will be slightly greater than .
If , and .
Since the total is greater than (due to the added base), the will be slightly less than 7.
Therefore, the will be slightly greater than 7.
The of the diluted solution is between 7 and 8.

The initial concentration of the strong acid is .
When diluted 10 times, the final concentration is:
.
The is calculated as .
.
The of the final solution is 5, which falls between 4 and 5.