Does water temperature increase at a uniform rate when heated with a bunsen burner?
I think the answer is no, but it's a long time since I studied thermodynamics. From memory it might be the second law of thermodynamics that you need.
It's definitely no - as the water heats, more collision causes more reactions - ergo the temperature rate increases faster.
More reactions of what? If water molecules don't react with other water molecules and even if they did, that would only be true if it was an exothermic reaction, it could be an endothermic reaction in which case the temperature would drop.
From memory, liquid water heats uniformly as it takes a certain amount of energy to raise it's temperature by 1 degree and the amount of energy is uniform, so as long as the bunsen burner provides a steady amount of energy the water will heat uniformly. However, once it reaches boiling point it will stay at 100 deg C (at standard pressure) until it has all evaporated. If you are trapping the steam then once it's all evoporated it will carry on heating beyond 100 deg C. The same is true of the transition from ice to liquid water.
I'm presuming Colts is just dealing with water in it's liquid state though.
Okay, ignore everything I just said (well most of it - the bit about reactions is right) a significant portion of my A-Level chemistry and Physics seems to have been pushed out the back of my memory banks.Idiot.
As Homer Simpson said Oggy - "Each time I learn something new it pushes something old out of my brain!". In my case, stuff seems to be dropping out even if I try really hard not to learn anything new.
Comments
I think the answer is no, but it's a long time since I studied thermodynamics. From memory it might be the second law of thermodynamics that you need.
In that case tell him a) to do his own homework and b) that it heats on a parabolic curve, as Leroy explained.
More reactions of what? If water molecules don't react with other water molecules and even if they did, that would only be true if it was an exothermic reaction, it could be an endothermic reaction in which case the temperature would drop.
From memory, liquid water heats uniformly as it takes a certain amount of energy to raise it's temperature by 1 degree and the amount of energy is uniform, so as long as the bunsen burner provides a steady amount of energy the water will heat uniformly. However, once it reaches boiling point it will stay at 100 deg C (at standard pressure) until it has all evaporated. If you are trapping the steam then once it's all evoporated it will carry on heating beyond 100 deg C. The same is true of the transition from ice to liquid water.
I'm presuming Colts is just dealing with water in it's liquid state though.
Okay, ignore everything I just said (well most of it - the bit about reactions is right) a significant portion of my A-Level chemistry and Physics seems to have been pushed out the back of my memory banks.Idiot.
Read this Colts, it might help.
D'accord, Exiled.
Agree entirely!