Daniel Tamosev
Badges: 7
Rep:
?
#1
Report Thread starter 1 year ago
#1
My teacher went through it however, one of the calculations was inconsistent with her answer so I need a way to answer the question:

In the TOF mass spectrometer, a germanium ion reaches the detector in 4.654 x 10 to the power of -6 s.
The kinetic energy of this ion is 2.438 x 10 to the power of -15 J.
The length of the flight tube is 96.00cm.

The kinetic energy of an ion is given by the equation KE=1/2mv2.

where
m=mass/kg
v=speed/ms-1

The Avogadro constant L = 6.022x10 to the power of 23 mol-1.

Use this information to calculate the mass, in g, of one mole of these germanium ions. Use your answer to state the mass number of this germanium ion.
0
reply
saura
Badges: 9
Rep:
?
#2
Report 1 year ago
#2
might be wrong but this is what i would do

i need to find out velocity so i would do distance divided by time. However i had to convert the distance into metres first. When i did distance divide time i got 20627.41728 as my velocity. I then arranged the KE equation as mass = 2KE divided by velocity squared. using this arranged equation I did 4.876 x 10 to the -5 divided by 425490343.5 (i did the squaring on the velocity and multiplying the KE by 2 beforehand). This got me 1.145971953 x 10 to the -13. I now multiply by 1000 and then multiply by avogadros constant to get 6.9 x 10 to the 13 (3 s.f)

now this might not be right or it might be right I just did this for practice
0
reply
omegabravo
Badges: 1
Rep:
?
#3
Report 11 months ago
#3
Yh I got this as well... but I doubted myself because I thought it was too big an answer
0
reply
14lololoE
Badges: 9
Rep:
?
#4
Report 11 months ago
#4
isnt that wrong tho the velocity is meant to be 206274.1727 not 20627.41727
0
reply
14lololoE
Badges: 9
Rep:
?
#5
Report 11 months ago
#5
(Original post by omegabravo)
Yh I got this as well... but I doubted myself because I thought it was too big an answer
isnt that wrong tho your meant to get what i put below as the velocity
0
reply
charco
Badges: 17
Rep:
?
#6
Report 11 months ago
#6
(Original post by Daniel Tamosev)
My teacher went through it however, one of the calculations was inconsistent with her answer so I need a way to answer the question:

In the TOF mass spectrometer, a germanium ion reaches the detector in 4.654 x 10 to the power of -6 s.
The kinetic energy of this ion is 2.438 x 10 to the power of -15 J.
The length of the flight tube is 96.00cm.

The kinetic energy of an ion is given by the equation KE=1/2mv2.

where
m=mass/kg
v=speed/ms-1

The Avogadro constant L = 6.022x10 to the power of 23 mol-1.

Use this information to calculate the mass, in g, of one mole of these germanium ions. Use your answer to state the mass number of this germanium ion.
K.E = 0.5 *m * v2 = 2.438 x 10-15 J

Time taken = 4.654 x 10-6 s
Distance = 96.00cm = 0.96 m

Velocity = Distance/time = 0.96/4.654 x 10-6 s = 206274.1728 ms-1
Velocity squared = 4.255 x 1010

m = 2 * 2.438 x 10-15/4.255 x 1010
m = 1.146 x 10-25 kg

m per mol = 1.146 x 10-25 x 6.0223 x 1023 = 0.0690 kg

mass of ion per mol = 69.0 g
1
reply
14lololoE
Badges: 9
Rep:
?
#7
Report 11 months ago
#7
yeah thats what me and my mates got and then as the mr we got 69
0
reply
idkkkkkk
Badges: 12
Rep:
?
#8
Report 4 weeks ago
#8
i have done this question somewhere before which paper was it in?
0
reply
omegabravo
Badges: 1
Rep:
?
#9
Report 4 weeks ago
#9
(Original post by idkkkkkk)
i have done this question somewhere before which paper was it in?
No idea... i don't even remember replying to this post lol
0
reply
JayEoly
Badges: 4
Rep:
?
#10
Report 2 weeks ago
#10
(Original post by idkkkkkk)
i have done this question somewhere before which paper was it in?
its from the 2019 chem AS paper 1
0
reply
ConfusedDemon
Badges: 16
Rep:
?
#11
Report 1 week ago
#11
OML, this is the first time i prolly got a 5 marker right, i just checked it against the answer that someone gave, AND AAHHHH I GOT ITTT!!!
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Do you think receiving Teacher Assessed Grades will impact your future?

I'm worried it will negatively impact me getting into university/college (43)
37.07%
I'm worried that I’m not academically prepared for the next stage in my educational journey (11)
9.48%
I'm worried it will impact my future career (5)
4.31%
I'm worried that my grades will be seen as ‘lesser’ because I didn’t take exams (29)
25%
I don’t think that receiving these grades will impact my future (18)
15.52%
I think that receiving these grades will affect me in another way (let us know in the discussion!) (10)
8.62%

Watched Threads

View All
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise