Explanation:
It is given that possible number of ways the Cl and Br can be absorbed initially are 100.
S, possible number of ways by which Br can be desorbed is as follows.

Now, we will calculate the change in entropy as follows.

where,
= Boltzmann constant = 
= change in entropy
Therefore, we will calculate the change in entropy as follows.

= 
= 
= 
Thus, we can conclude that the change in entropy is
.
Iron filings can be attracted by the magnet whereas salt can not. So the mixture can be separated by a magnet
Answer:
A. Substance E
A. Substance C
A. Substance A
Explanation:
Given that:
At 4 °C, Substance E has a vapor pressure of 86. torr and Substance F has a vapor pressure of 136. torr
Which has a higher boiling point?
A. Substance E
B. Substance F
C. Neither,EandF have the same boiling point
The vapor pressure varies inversely proportional to the boiling point.

Therefore, the lower the vapor pressure, the higher the boiling point.
At 4°C, Substance E with a lower vapor pressure of 86. torr will have a higher boiling point from the given information.
2.
Recall that :

therefore, the lower the enthalpy of vaporization, the higher the vapor pressure at any given temperature.
Given that:
Substance C has an enthalpy of vaporization smaller than that of substance D. Then, substance C has a higher vapor pressure.
3.
We've earlier said that:
The vapor pressure varies inversely proportional to the boiling point.

Therefore, the lower the vapor pressure, the higher the boiling point.
As such, Substance A will have a higher boiling point.
% by mass = (mass solute/mass solution)*100%
mass of the solute = 54.7 g
mass of the solution = mass solute + mass solvent=54.7+500=554.7 g
% by mass = (54.7/554.7)*100%≈0.0986*100% = 9.86%