Mod 3 Flashcards
What is first ionisation energy
. Energy needed to remove one mole of electrons from one mole of gaseous atoms to form one mole of gaseous 1+ ions
. In equation always include state symbols and correct charges
What exceptions are there in first ionisation energy
. Between groups 2 to 3 there is a decrease
. MGs outer electron in three a sub shell and Al in 3p sub shell 3p has higher energy level so slight increase in shielding
. Between group 5 to 6 there is a decrease
. Shielding identical and electron being removed from 3p sub shell so sulfur is easier to remove
What is second ionisation energy
. The energy needed to remove one electron from each ion in one mole of gaseous 1+ ions to form one mole of gaseous 2+ ions
What are the trends in successive ionisation energies
. Increase is more electrons are removed
. Electrons are removed from a more positive ion
. Attraction between remaining electrons and nucleus increases radius also decreases
. more energy needed to remove the next electron
Explain the trend in reactivity in group 2 metals
. Reactivity increases down the group as shielding increases atomic radius increases nuclear charge increases but is outweighed by increasing atomic radius and shielding so nuclear attraction of outer electron decreases so less energy required to remove electrons
Explain group 2 metals solubility with sulphate and hydroxide
. Sulphate solubility increases up the group
. Hydroxide solubility increases down the group
What use does CA(OH)2 have
. Using agriculture to neutralise acidic soils
What are use does MG(OH)2 and CACO3 have
. Used an indigestion tablets antacids to neutralise excess stomach acid
What are used to BaSO4 has
. Barium meals because BASO4 is insoluble
What is periodicity
. Repeating pattern in chemical and physical properties
What is the trend in atomic radius across a period and across a group
. Decreases across period as number of protons increases so I was for electrons in the same shell have similar shielding so strong nuclear attraction makes electrons be drawn in more
. Increases down the group as number of shells increases
Describe Melting and boiling points down Group 8
. Number of electrons in atomic radius increases the strength of induced dipole dipole interactions increases which requires more energy to overcome
Explain the trending reactivity in halogens
. Less reactive down the group as atomic radius increases so outer electrons further from nucleus and more shielded so less nuclear attraction so more difficult to attract electrons
Explain displacement reactions in halogens
. More reactive halogens will oxidise halide ions of less reactive halogens
What colour do chlorine bromine and iodine go in aqueous halogens And when dissolved in organic solvent
. In aqeous halogens pale green, orange, brown
. Inorganic solvent pale green, orange, violet
