top of page

# ToF Mass Spectroscopy

#### 2017 Paper One

##### Question Four

###### If you haven't gone through the question/paper, click the direct link below, and have a go...

###### AQA A-level CHEMISTRY Paper 1 Inorganic and Physical ChemistryTuesday 13 June 2017

###### An 8-mark, 4-part question

###### The relative atomic mass of titanium is 47.8 to one decimal place.

###### Â

###### Use the m/z value in the table = 46

###### Mass of one atom of Ti-49:

###### Don't forget to convert to kilograms.

###### Â

###### The kinetic energy is a constant as is the length of the tube

###### Here's one way (a little rearranging is required)...

###### the length of the tube is the same for both ions, so...

###### The kinetic energy is a constant as is the length of the tube for both ions. L, of course, is also a constant - we can cancel them out.

###### The time of flight for the ion is:

###### Note: there are other ways to solve this.

###### This question proved a step too far for a lot of students with many gaining no marks. The manipulation is fairly straightforward - I would brush up on maths skills if you found this difficult

bottom of page