Mass Spectrometer Watch

LuisMarie
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- The relative mass of Z is 91.2 , being the element Zirconium (Zr).
- State how vaporized atoms of Z are converted into Z^+ ions in a mass spectrometer.
- State and explain which of the Z^+ ions formed from the isotopes of Z in part (c) will be deflected the most in a mass spectrometer.
- Explain briefly how the relative abundance of an ion is measured in a mass spectrometer.
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alow
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What have you tried?
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shohaib712
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1) Electron is removed from the atoms outershell by hitting it with electrons via the electron gun, causing an ion with an overall charge to be positive (Z into Z^+)
2) The ions with the least amount of neutrons (lower mass number) will deflect most at a greater speed compared to the ions with a lager mass number (more neutrons). This is because the lighter the isotope, the greater the deflection
3) Its measured by the detector which signal the information onto the mass spectrum which compares the mass of each isotopes of that element to its relative percentage abundances

I learnt the topic on my own - so my answers could be incorrect.
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Jpw1097
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(Original post by shohaib712)
1) Electron is removed from the atoms outershell by hitting it with electrons via the electron gun, causing an ion with an overall charge to be positive (Z into Z^+)
2) The ions with the least amount of neutrons (lower mass number) will deflect most at a greater speed compared to the ions with a lager mass number (more neutrons). This is because the lighter the isotope, the greater the deflection
3) Its measured by the detector which signal the information onto the mass spectrum which compares the mass of each isotopes of that element to its relative percentage abundances

I learnt the topic on my own - so my answers could be incorrect.
Your answers seem fine. It wouldn't be required, but for part 2, the electromagnet creates a magnetic field that interacts with the ions and exerts a force on them - causing them to be deflected. Using the equation F=ma, you can see that for a given force, lighter isotopes will have greater acceleration and hence will be deflected more and vice versa. For part 3, you could mention that when cations hit the detector, electrons flow from the detector (a metal plate) to the ions causing a current to flow. The relative intensity of the isotopes are proportional to the size of the current - you may be required to know this however.
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shohaib712
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(Original post by Jpw1097)
Your answers seem fine. It wouldn't be required, but for part 2, the electromagnet creates a magnetic field that interacts with the ions and exerts a force on them - causing them to be deflected. Using the equation F=ma, you can see that for a given force, lighter isotopes will have greater acceleration and hence will be deflected more and vice versa. For part 3, you could mention that when cations hit the detector, electrons flow from the detector (a metal plate) to the ions causing a current to flow. The relative intensity of the isotopes are proportional to the size of the current - you may be required to know this however.
Wow!!! How do you know all this? My textbook doesn't mention any of this, sadly.
Im a bit confused on the second part,
So the electrons from the metal plate (detector) flow to the ions, and this causes a current to fow? why has a current been created?

Can you explain what relative intensity means? Sory for alll the questions
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shohaib712
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(Original post by Jpw1097)
Your answers seem fine. It wouldn't be required, but for part 2, the electromagnet creates a magnetic field that interacts with the ions and exerts a force on them - causing them to be deflected. Using the equation F=ma, you can see that for a given force, lighter isotopes will have greater acceleration and hence will be deflected more and vice versa. For part 3, you could mention that when cations hit the detector, electrons flow from the detector (a metal plate) to the ions causing a current to flow. The relative intensity of the isotopes are proportional to the size of the current - you may be required to know this however.
Oh so the lower the mass, the greater the acceleration - when the ions are accelerated during the process?

Whats the electromagnet? Man, your sooo clever! It feels like your combining physics with it?
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Jpw1097
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(Original post by shohaib712)
Wow!!! How do you know all this? My textbook doesn't mention any of this, sadly.
Im a bit confused on the second part,
So the electrons from the metal plate (detector) flow to the ions, and this causes a current to fow? why has a current been created?

Can you explain what relative intensity means? Sory for alll the questions
http://www.chemguide.co.uk/analysis/...owitworks.html

I recommend you check out the link, it should have everything you need to know.

Electrons are negatively charged while the cations are positively charged, therefore the electrons are attracted to the cations and flow towards the cation - neutralising the charge of the ion. This causes a flow of electrons - this, by definition, is a current. A current is a flow of charge/electrons.

Relative intensity is essentially the same thing as relative abundance.

(Original post by shohaib712)
Oh so the lower the mass, the greater the acceleration - when the ions are accelerated during the process?

Whats the electromagnet? Man, your sooo clever! It feels like your combining physics with it?
Lighter ions (or those with a lower m/z ratio) will be accelerated more and will hence be deflected more. The electromagnet creates the magnetic field required to deflect the ions during deflection. This happens in the curved part of the mass spectrometer. An electromagnet is essentially a coil of wire, a current-carrying wire produces a magnetic field. An electromagnet is used as opposed to a permanent magnet because the magnetic field strength can be varied by varying the size of the current in the wire, and the electromagnet can be turned on and off unlike a permanent magnet.
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shohaib712
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(Original post by Jpw1097)
http://www.chemguide.co.uk/analysis/...owitworks.html

I recommend you check out the link, it should have everything you need to know.

Electrons are negatively charged while the cations are positively charged, therefore the electrons are attracted to the cations and flow towards the cation - neutralising the charge of the ion. This causes a flow of electrons - this, by definition, is a current. A current is a flow of charge/electrons.

Relative intensity is essentially the same thing as relative abundance.



Lighter ions (or those with a lower m/z ratio) will be accelerated more and will hence be deflected more. The electromagnet creates the magnetic field required to deflect the ions during deflection. This happens in the curved part of the mass spectrometer. An electromagnet is essentially a coil of wire, a current-carrying wire produces a magnetic field. An electromagnet is used as opposed to a permanent magnet because the magnetic field strength can be varied by varying the size of the current in the wire, and the electromagnet can be turned on and off unlike a permanent magnet.
Thank you so much for the help! It was vaguely explained for module 2, thats why my revision book didnt explain in detail. However there is a large section about it but its for module 4 lol
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