Chemistry paper corrections Flashcards
Group 7
Fluorine, Chlorine, Bromine, Iodine
Fluorine is yellow and a gas at room temp
Chlorine is green and a gas at room temp
Bromine is red/brown and a liquid at room temp
Iodine is dark grey and solid at room temp
AS you go down group 7, they get less reactive
Similarities in diamond and graphite
Covalent bonds
Giant structure
Both allotropes of carbon
Differences in diamond and graphite
Diamond has 4 bonds, 3D structure, higher melting point and not a conductor
Graphite has 3 bonds, layers of carbon, lower melting point and is a conductor
Why is Diamond harder than graphite
All bonds are strong in diamond but there are weaker bonds between layers in graphite
Why is graphite a conductor
Graphite has delocalised electrons that can carry a charge but diamond doesnt
Key points about ionic and simple covalent bonding
Ionic compounds are held together by strong forces between ions which means a higher boiling and melting point and more energy needed to separate
Small simple covalent molecules have weaker forces so a lower melting and boiling point and less energy to separate.
Why is the metal sometimes not formed at the negative electrode
The metal may be more reactive than anything else such as hydrogen and does noth get displaced
Why cant the Haber process produce 100% yield
It is reversible so the products react as soon as they’re formed
Difference between formulation and a pure substance
A formulation is a mixture whereas a pure substance is a single substance
Moles formula
Moles=mass/RFM
What is dynamic equilibrium
When forward and reverse reaction occur at the same rate
