[Flux]

the question says that nitrogen trichloride has 3 isotopes, N-14, Cl-35, Cl-37.
It wants the number of lines found in the mass spectrum which correspond to the molecular and fragmented molecular ions excluding atomic ions.

I got 11, but the answer was 9. please help me



PS:there's another question, i decided to post them together though.
The relative atomic mass of zinc is 65.37 and its density is 7.14gram per cm cube. What is the volume of 1 atom of zinc give that the Avogadro constant = L per mole or L mol^-1
Answer : (65.37)/( 7.14 x L )

I know this question is very maths with the algebra thing, but I can't figure an approach to getting the answer without jumbling up all the units.

Im really really new to A-level equivalent Chemistry, so I'm trying my best.

[sjb]

the question says that nitrogen trichloride has 3 isotopes, N-14, Cl-35, Cl-37.
It wants the number of lines found in the mass spectrum which correspond to the molecular and fragmented molecular ions excluding atomic ions.

I got 11, but the answer was 9. please help me

What are the formulas of the species you have identified?

PS:there's another question, i decided to post them together though.
The relative atomic mass of zinc is 65.37 and its density is 7.14gram per cm cube. What is the volume of 1 atom of zinc give that the Avogadro constant = L per mole or L mol^-1
Answer : (65.37)/( 7.14 x L )

I know this question is very maths with the algebra thing, but I can't figure an approach to getting the answer without jumbling up all the units.

Im really really new to A-level equivalent Chemistry, so I'm trying my best.

What is the volume of one mole of zinc?

[Flux]

the question says that nitrogen trichloride has 3 isotopes, N-14, Cl-35, Cl-37.
It wants the number of lines found in the mass spectrum which correspond to the molecular and fragmented molecular ions excluding atomic ions.

I got 11, but the answer was 9. please help me

What are the formulas of the species you have identified?

PS:there's another question, i decided to post them together though.
The relative atomic mass of zinc is 65.37 and its density is 7.14gram per cm cube. What is the volume of 1 atom of zinc give that the Avogadro constant = L per mole or L mol^-1
Answer : (65.37)/( 7.14 x L )

I know this question is very maths with the algebra thing, but I can't figure an approach to getting the answer without jumbling up all the units.

Im really really new to A-level equivalent Chemistry, so I'm trying my best.

What is the volume of one mole of zinc?

I'll try to type it down although I have no idea how to express some of these fragments ><

N-N
N-Cl35
N-Cl37
Cl35-Cl35
Cl37-Cl37
Cl35-Cl37
N-Cl35-Cl37
N-Cl35-Cl35
N-Cl37-Cl37
N-N-Cl35
N-N-Cl37

2) volume of one mole of zinc eh, erm, that would be RAM/density [ 65.34/7.14 ] ?
eh im not sure on this

[sjb]

I'll try to type it down although I have no idea how to express some of these fragments ><

N-N
N-Cl35
N-Cl37
Cl35-Cl35
Cl37-Cl37
Cl35-Cl37
N-Cl35-Cl37
N-Cl35-Cl35
N-Cl37-Cl37
N-N-Cl35
N-N-Cl37

What is the structure of nitrogen trichloride (which atoms are bonded to which)? Some of these are right , but not others.

2) volume of one mole of zinc eh, erm, that would be RAM/density [ 65.34/7.14 ] ?
eh im not sure on this

Yes, so if one mole has this volume, what does Avogadro's number tell you?

[Flux]

1) Actually I have yet to learn about that, since I just randomly took up these Chemistry books [volume 1 and 2] from my sister. So I started with Volume 1 Chapter 1. [I'm starting my A-levels next year, thought it would be good to have a look at the syllabus]

2) I see, so when volume of one mole divides by Avogadro's constant, i get the volume of one zinc atom. so the key is being able to play around with the units I guess?

[sjb]

Hmm, if it's chapter 1, volume 1, perhaps you'd be given the structure - so if I say that it's NCl₃, with each of the chlorines only bonded to the nitrogen,  does that help?

As to part 2, yes, I think that's probably the reason here.

[Flux]

well I guess it does help, but wouldn't it be assumed that the nitrogen trichloride molecule is passed through a mass spectrometer, where all the elements would jumble up and form all kinds of different compound?

Or is there a way to predict how would the elements bond with each other?

[sjb]

My understanding is that the MS typically ionises and often breaks bonds, but that they do not usually reform.

What isotopologues (http://en.wikipedia.org/w/index.php?title=Isotopologue&oldid=392230094) can you write for a compound with formula NCl₃, for instance?

[Flux]

oh, so does it mean the ones below does not occur?

N-N-Cl35
N-N-Cl37
N-N

so does the below occur?

Cl35-Cl35-Cl35
Cl37-Cl37-Cl37
Cl35-Cl37-Cl37
Cl37-Cl37-Cl35

I'm sorry if I'm being slow here, but I've really not learned anything about this, so it's hard to even know where to start.

[sjb]

With a ¹⁴N attached, yes.

So you have

• ¹⁴N³⁵Cl
• ¹⁴N³⁷Cl
• ¹⁴N³⁵Cl³⁵Cl
• ¹⁴N³⁵Cl³⁷Cl
• ¹⁴N³⁷Cl³⁷Cl
• ¹⁴N³⁵Cl³⁵Cl³⁵Cl
• ¹⁴N³⁵Cl³⁵Cl³⁷Cl
• ¹⁴N³⁵Cl³⁷Cl³⁷Cl
• ¹⁴N³⁷Cl³⁷Cl³⁷Cl

[Flux]

ok here's a question, why must it have a Nitrogen attached to it?

[sjb]

If you look at the structural formula, the only species that allows for detachment of nitrogen is a chlorine atom, which in this case is excluded by the "excluding atomic ions" rider in the question.