periodicity of period 3 oxides

Question 1

explain the trends in melting points across the period 3 oxides

Answer 1

• the metallic oxides (Na2O, MgO, Al203) melting point increases due to them having a greater charge on the metal ion, with the same amount of electrons but one more proton each time charge increases so the attraction between the outer electron and nucleus is stronger due to a smaller atomic radii.
• and they are ionically bonded so they have a great ionic lattice structure with lots of strong ionic forces between oppositely charged ions
• there is a large jump as Si02 has a giant covalent structure which has lots of strong electrostatic forces between shared pair of electrons
• there is then a great decrease in melting point due to P4O10 and SO2 being a simple molecular structure meaning they only have wdw which require a lot less energy to overcome

Question 2

when dissolved in water what type of oxide does Na20 form

Answer 2

basic oxide

Question 3

when dissolved in water what type of oxide does MgO

Answer 3

basic oxide

Question 4

when dissolved in water what type of oxide does Al2O3 form

Answer 4

amphoteric
(reacts as both an acid or a base)

Question 5

define amphoteric

Answer 5

reacts as both an acid or a base

Question 6

when dissolved in water what of oxide does P4O10 form

Answer 6

acidic

Question 7

when dissolved in water what type of oxide does SO2/SO3 form

Answer 7

acidic