Introduction to organic chemistry

Question 1

what over all charge do atoms have ??

Answer 1

Atoms have no overall charge

Question 2

how would you work out the relative atomic mass ?? (with a percentage)

Answer 2

(%xmass) + (%xmass) + (%xmass) ÷100

Question 3

how would you work out the relative atomic mass??? (using amount not percentage)

Answer 3

amount = A (Axmass)+(Axmass)+(A×mass)÷(The total of all the As)

Question 4

What does ToF stand for

Answer 4

Time of flight

Question 5

What are the four stages of time of flight mass spectrometry

Answer 5

1) ionisation
2) Acceleration of ions
3) separation of charged ions
4) detection

Question 6

What are the two things might happen during ionisation

Answer 6

Electron impact
OR
Electrospray ionisation

Question 7

What is electron impact used for

Answer 7

Elements and low Mr compounds

Question 8

What does high electron impact do

Answer 8

High energy electrons are fired at the sample from a electron gun
This knocks off one electron from each atom/ molecule to form 1+ ion X(g) -) XH+(g)

Question 9

What is electrospray ionisation used for

Answer 9

High Mr compounds (eg proteins)

Question 10

What happens in electrospray ionisation

Answer 10

The sample is dissolved in a volatile solvent and injected through a fine hypodermic needle as a fine spray into a vacuum in the ionisation chamber
A very high voltage is applied to the end of the needle where the spray emerges (the needle is positively changed)
The particles gain a protein and becomes positive 1+

Question 11

What happens during the acceleration of ions

Answer 11

The ions are accelerated using an electric field so that all of the ions have the same kinetic energy

Question 12

What is the formula for kinetic energy

Answer 12

Kinetic energy = 1/2mv2

Question 13

What happens during during the separation of charged ions

Answer 13

Ion drift ( ions enter the flight tube)
Ions with different masses have a different time of flight
The lighter ions travel faster and take less time to reach the detector

Question 14

What is the equation for time of flight

Answer 14

_________
T = d / M
/. —

Question 15

What is the detector in time of flight mass spectrometry

Answer 15

A negatively charged plate

Question 16

In time of flight mass spectrometry what is produced when the ions hit the plate

Answer 16

A current (the more ions the bigger the current)

Question 17

How meny electrons can you have in an ‘S’ shell

Answer 17

2

Question 18

How meny electrons are in a ‘P’ shell

Answer 18

6

Question 19

How meny electrons are in a ‘d’ shell

Answer 19

10

Question 20

Which two elements work differently to the electronic configuration Oder

Answer 20

Chromium and copper

Question 21

What do the two exception electrons do in their electron configuration

Answer 21

They move electrons to have a full outer shells and the second last shell has a half outer shell

Question 22

What is ionisation energy

Answer 22

The energy needed to ionise an electron. As you go down the group you need less energy to ionise the electron

Question 23

What is iso electric

Answer 23

When elements are different but have the same electronic structure (all of these would react the same)

Question 24

Which energy level will transition metals always lose before their 3D electrons

Answer 24

4s

Question 25

What is this equation called Li —) Li+ + e-

Answer 25

An ionisation equation

Question 26

Why does reactivity increase as you go down a group

Answer 26

Because the electrons are further away from the nucleus because their is less forces of attraction

Question 27

Why would magnesium (group 3) take more energy to receive compared to the atom before it in a period

Answer 27

Because it has the same number of shells at the element before however has more protons and theirfor will have stronger forces of attraction

Question 28

What is electron pair repeltion

Answer 28

Where electrons are paired because there is no more space and so repel each other

Question 29

Why does the sixth element always need less energy to ironise than the element before in a period

Answer 29

Because it experiences electron pair repletion because it’s electrons are having to share a part of a shell therefor the electrons are already repelling each other so it takes less energy to stop this

Question 30

What is empathy change formation

Answer 30

It is when you make 1 mole of something

Question 31

What is the equation for atom economy

Answer 31

Designed product | Atom economy = —

Question 32

If only one product was produced form a reaction what would the atom economy be .

Answer 32

100%

Question 33

Explain how ions are accelerated detected and have their abundance determined in a time of flight mass spectrometer [3 marks]

Answer 33

The ions are accelerated by an electric field Where the ions are detected by gaining electrons And the abundance is determined by the size of the current flowing in the detector

Question 34

How would you calculate the mass of an element using its abundance e of isotopes

Answer 34

Awnser = (%abundance x mass) and so on plus (%abundance of unknown x ?) Then you would rearrange the formula