Consider two flasks that contain different pure substances at 20 degree C. The s
ID: 476603 • Letter: C
Question
Consider two flasks that contain different pure substances at 20 degree C. The substance in one flask (substance A) has a molar mass of 100g/mol and can form hydrogen bonds between molecules. The other substance (B) has a molar mass of 105 g/mol and has dipole-dipole IMF. Assuming that both molecular structures are similar (no significant difference in surface area), which flask contains substance A? Explain. If the temperature of each flask is increased by 15 degree C, how would the pictures change (assuming you stay below the boiling points of both)?Explanation / Answer
(a) Left side Falsk indicates Substance 'B'
Right side flask indicates Substance 'A'
It is because Substance A has hydrogen bonding interactions which are more effective than dipole dipole interactions presentamong the molecules of substance B. So, less number of molecules of substance A are in vapour phase than that of substance B at the same 20 degree C temperature.
(b) By increasing the temperature, the number of vapour phase molecules of both the substances will increase.But still the number of molecules of substance B is more than that of substance A.