C1

Question 1

What is the equation that shows an element being ionised, e.g. Calcium

Answer 1

Ca(g) —–> Ca+(g) + e-

The ion on the right is always minus 1 its usual charge as an electron has been added on.

Question 2

Group 2 first ionisation energy trend

Answer 2

It decreases down the group, this is because as you go down the group, the atom increases in size. This means that there are more inner shells in the atom shielding the valence shell from the nuclear charge. As a result, as you go down the group, this shielding effect increases therefore it is easier to remove the outer electron as the efa between the valence electron and nucleus is less.

Question 3

PERIOD 3 greatest boiling point

Answer 3

Silicon has the greatest boiling point in period 3 as it has many strong covalent bonds that require lots of energy in order to break, which require more energy to break than the metallic bonds in Na, Mg and Al whilst also requiring more energy than the van der waal forces in P, S and Cl/Ar.

Question 4

PERIOD 3 greatest firs ionisation energy

Answer 4

Argon as it has the most protons, therefore it has the largest nuclear charge, whilst having the same amount of inner shells than the rest of the element. Therefore it will require the most electron to remove its first valence electron.

Question 5

Why are the noble gases not assigned an electronegativity value?

Answer 5

As they do not form covalent bonds, therefore since electronegativity is an atoms ability to attract a bonding pair of electrons it cannot have this.

Question 6

What is the most electronegative element in period 3?

Answer 6

Cl

Question 7

Trend in ionisation energies for a given element?

Answer 7

The first ionisation energy for one element will be less than the second as it is further away from the nucleus, therefore its efa is weaker.

Question 8

What do we call the transition metals in the periodic table?

Answer 8

D block

Question 9

What happens during stage 1: ionisation?

Answer 9

During stage 1: 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, then a very high voltage is applied to the tip of a needle where the spray emerges, the particles gain a proton and become ions as a fine mist, the solvent then evaporates.

Question 10

What happens during stage 2: Accelaration?

Answer 10

Ions are accelerated using an electric field so that they all have the same Kinetic Energy.

Question 11

What happens during stage 3: Separation of charged ions?

Answer 11

Ion drift will occur, this is when ions enter the flight tube. The heavier ions will be slower whereas the lighter ions will have a greater velocity and reach the detector quicker

Question 12

What happens in stage 4: Detection?

Answer 12

The ions hit a negatively charged plate, when the ions hit this plate a current is produced, the more ions that hit the detector the bigger the current.

Question 13

What is true of organic molecules?

Answer 13

They often have a tiny peak of Mr+1 due to a small number of molecules containing either or 13C or 2H atoms.

Question 14

How to find the relative molecular mass of a molecule using mass spectrometry?

Answer 14

The peak with the highest m/z ration, even if it has the lowest abundance, is the relative molecular mass of that molecule.

Question 15

Why do isotopes have the same chemical properties?

Answer 15

As chemical properties depend on the amount of outer electrons, and ions have the same amount of electrons.

Question 16

How do you find the mass in 1 mole of an atom?

Answer 16

Divide the relative mass by Avogadro’s constant. e.g. 23/6.02 x 10^23

Question 17

What is relative atomic mass?

Answer 17

(Average mass of atom/mass of 1 atom of 12C) x 12

Question 18

How do you find the relative atomic mass of an atom via mass spec?

Answer 18

Multiply the m/z of each peak by its abundance. Do this for each peak and add them up, then divide by the total relative abundance.

Question 19

What is electronegativity?

Answer 19

Electronegativity is the power of an atom to attract the electron density in a covalent bond towards itself.

Question 20

What is true about the boiling point of atoms/molecules?

Answer 20

The bigger an atom, the greater its boiling point will be. This is because there are more electrons, which means greater e.f.a, or greater intermolecular forces.

Question 21

What is a dative covalent bond?

Answer 21

A covalent bond in which only one atom donates the bonding electron pair

Question 22

Why does magnesium have a higher boiling point than sodium?

Answer 22

As it has a greater ionic charge, (+2 compared to +1), therefore the e.f.a attraction between the ion and sea of delocalised electrons is greater.

Question 23

Why does diamond/graphite have a high boiling point?

Answer 23

As they are macromolecular and have a giant covalent structure, therefore there are lots of strong covalent bonds all throughout its crystalline structure that require lots of energy to break.

Question 24

Why does graphite conduct electricity?

Answer 24

As it has free delocalised electrons that run throughout its structure, as each C atom is only covalently bonded to 3 other C atoms, therefore this means that there is 1 valence electron per C atom able to carry charge through its structure.

Question 25

Why is graphite soft?

Answer 25

Due to the weak van der waal forces in between each layer that can easily break

Question 26

Why is graphite used as a lubricant?

Answer 26

The layers can easily slide over each other as they are held by weak van der waal forces.

Question 27

Why in a trigonal planar structure is the angle 120 degrees? (3bp, 0lp)

Answer 27

As each bonding pair of electrons repel each other an equal amount

Question 28

Why do lone pairs of electrons subtract degrees of an angle?

Answer 28

As lone pairs repel the bonding pairs more than other bonding pairs.

Question 29

What is the bonding in a crystal of a diatomic molecule like I2?

Answer 29

Covalent Bonding

Question 30

Why is energy needed to melt a crystal of a substance?

Answer 30

You have to break the intermolecular forces holding it together.

Question 31

What are all the types of crystals?

Answer 31

Metallic crystals.
Ionic crystals.
Covalent crystals.
Molecular crystals.

Question 32

What is the difference between a molecular crystal and a covalent crystal?

Answer 32

Covalent crystals are composed of atoms which are covalently bonded to one another. Molecular crystals are held together by weak intermolecular forces.

Question 33

How is the electric current created?

Answer 33

Electrons are transferred from the detector to the negative plate.

Question 34

How is the mass spectrometer able to identify between 2 species?

Answer 34

Each species will have different masses, which means that they will have different velocities (equal KE) therefore the species with the lower m/z ratio will arrive at the detector plate first

Question 35

Why is the first ionisation energy of Sulfur lower than Phopshorus

Answer 35

As in Sulfur, its valence electrons in the 3p orbital are paired, therefore, since they repel each other it will require less energy to remove than the valence electron in the 3p orbital of phosphorus, as that is unpaired.