IMAT 2021 Chemistry

Hi, can anyone help me with this question? Thank you so much!!!


a solute decreases the freezing point of solution so 1) wrong
lower temperature = lower kinetic energy so 2) wrong
when atmospheric pressure increases, the boiling point increases so 3) correct

hope this helps!


Hi, can I ask more questions? I’ve searched it Internet but I want to be more certain.

  • What is relationship between solute and boiling point, melting point?
  • What is relationship between atmospheric pressure and freezing point, melting point?
  • What is relationship between temperature and boiling point, freezing point, melting point?
    Hope I don’t bother you too much! Thank you very much for helping me!!!

Hi! of course!

in my opinion:
solute increases the boiling point (= if you put salt into a pot of water it takes longer to boil than without salt, and you have to turn your stove on hotter)

solute decreases melting point since it disrupts IMF (is this correct guys?)

solute decreases freezing point (we add salt to icy roads to lower the freezing point, it now needs to be much colder outside for the snow to stay solid)

There’s a more “scientific” way of answering this but i find little examples is all we need to remember to solve the questions

with atmospheric pressure:
at high altitudes Patm is low and boiling point is low (at sea level water boils at 100°C, on top of mount Everest at 70-80°C!!)

otherwise here is a good quick video about phase diagrams: Phase Diagrams of Water & CO2 Explained - Chemistry - Melting, Boiling & Critical Point - YouTube
you can see that when we raise the pressure, the temperature needed to go from liquid to gas increases, so this means the boiling point increases
knowing the phase diagram of H20 and CO2 are quite useful to know :wink:

Hope this helps!


Thank you so much!!! I hope you have a great day!

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