• Best of luck to the class of 2024 for their HSC exams. You got this!
    Let us know your thoughts on the HSC exams here
  • YOU can help the next generation of students in the community!
    Share your trial papers and notes on our Notes & Resources page
MedVision ad

Radiation Question (1 Viewer)

sam5

Member
Joined
Jun 28, 2009
Messages
473
Gender
Male
HSC
2009
If i had a radioactive anion, and i reacted it with Fe ions, would the resulting compound be radioactive?

Also, could this property be used to demonstrate how reaction rates are equal in a system at equilibrium?

Thanks a lot.
 

iSplicer

Well-Known Member
Joined
Jun 11, 2008
Messages
1,809
Location
Strathfield
Gender
Male
HSC
2010
Uni Grad
2017
If i had a radioactive anion, and i reacted it with Fe ions, would the resulting compound be radioactive?

Also, could this property be used to demonstrate how reaction rates are equal in a system at equilibrium?

Thanks a lot.
Yes, you are 100% correct!

As long as the product contains the atoms which were initially radioactive for whatever reason (perhaps an inbalanced p:n ratio?) it will be radioactive. And yes, that is how we show that the forward and backward rates of reaction are equal in a system of equilibrium!
 

sam5

Member
Joined
Jun 28, 2009
Messages
473
Gender
Male
HSC
2009
Yes, you are 100% correct!

As long as the product contains the atoms which were initially radioactive for whatever reason (perhaps an inbalanced p:n ratio?) it will be radioactive. And yes, that is how we show that the forward and backward rates of reaction are equal in a system of equilibrium!
thankyou.... but how can it be proven with the equilibrium? i.e. how exactly can radiation show that reaction rates are equal when in equilirium?

i know ur only a high schooler, and i did hsc chem and got 85, but ur at baulkam hills.
 

iSplicer

Well-Known Member
Joined
Jun 11, 2008
Messages
1,809
Location
Strathfield
Gender
Male
HSC
2010
Uni Grad
2017
thankyou.... but how can it be proven with the equilibrium? i.e. how exactly can radiation show that reaction rates are equal when in equilirium?

i know ur only a high schooler, and i did hsc chem and got 85, but ur at baulkam hills.
Alright, well you know that all saturated solute systems are systems under equilibrium. THat is, for a solution which has been saturated to the point where there is leftover solid, the rate at which the the solid is falling out of the solution is equal to the rate at which the the solid is dissolving into the water.

For example, let us consider a lead nitrate solution which has been supersaturated, with a substantial amount of lead nitrate crystals still undissolved. Now, if we were to add RADIOACTIVE lead nitrate crystals into our beaker, we get interesting results. Note at this point, only the added crystals are radioactive, not the initial solution. But if you wait a while and take a sample of the supernatant solution, you find that the solution has also become radioactive (it emits beta particles). If you repeat this after 3 hours, then again after 3 hours, etc, you find that at all these times the same amount of radiation is observed. This demonstrates that there are both forward and backward reactions taking place (some of the initially clean dissolved lead nitrate must have precipitated out, and some radioactive lead nitrate must have dissolved in). And the constancy of the radiation detected shows that the reactions proceed at the same rate once equilibrium has been achieved - which im sure lies far to the right!
 

sam5

Member
Joined
Jun 28, 2009
Messages
473
Gender
Male
HSC
2009
Alright, well you know that all saturated solute systems are systems under equilibrium. THat is, for a solution which has been saturated to the point where there is leftover solid, the rate at which the the solid is falling out of the solution is equal to the rate at which the the solid is dissolving into the water.

For example, let us consider a lead nitrate solution which has been supersaturated, with a substantial amount of lead nitrate crystals still undissolved. Now, if we were to add RADIOACTIVE lead nitrate crystals into our beaker, we get interesting results. Note at this point, only the added crystals are radioactive, not the initial solution. But if you wait a while and take a sample of the supernatant solution, you find that the solution has also become radioactive (it emits beta particles). If you repeat this after 3 hours, then again after 3 hours, etc, you find that at all these times the same amount of radiation is observed. This demonstrates that there are both forward and backward reactions taking place (some of the initially clean dissolved lead nitrate must have precipitated out, and some radioactive lead nitrate must have dissolved in). And the constancy of the radiation detected shows that the reactions proceed at the same rate once equilibrium has been achieved - which im sure lies far to the right!
thanks very much mate.... took me 2 times of reading it but i understand.

Dont worry, i wont be majoring in chemistry. I do biomed, so no more chem after this year!
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top