reactivity Trends Flashcards
Why is group 2 element called a reducing agent?
Because it has reduced another species by losing its two electrons to that species
How do group 2 elements react with water ?
Form an alkaline hydroxide and hydrogen gas
Why are g2 elements called alkaline earth metals?
Cuz of the alkaline properties of the metal hydrides
Define first ionisation energy
The energy required to remove on electron from each atom in one mole of gaseous atoms
Define 2nd ionization energy
The energy required to remove an electron from each ion in one mole of gaseous +1 ions to form one mole of gaseous +2 ions
give an example of how g2 compounds are used in medicine
G2 bases like magnesium and ca carbonates r used as acid indigestion tablets
what is ‘milk of magnesia’
a suspension of white mg(oh)2 in water , it is only very slightly soluble in water
explain why boiling point increases down g7 group
more electrons , stronger london forces, more energy required to break the intermolecular forces and boiling point increases
halogen = oxidising agent why?
anotehr species loses electrons to the halogen atom therefore it has oxidised another species and is an oxidising agent
how do you carry out a halogen-halide displacement reaction test.?
add each halogen to an aq solution of the other halides, if the halogen added is more reactive than the halide then a reaction takes place, the halogen displaces the halide present and the solution changes colour
what reactions in the halogen halide displacement reaction lead to a colour change
chlorine halogen with bromide (orange)and iodide ion (violet) , bromine halogen with iodide ion (violet).
how to tell difference between bromine (Orange) and iodine (brown) solution in water?
place in cyclohexane and iodine will turn violet and bromine will remain brown
why do halogens decrease in reactivity down the group?
increase in atomic radius and so innrshells increase = more shielding = weaker nuclear attraction to ccapture an e’ from anotehr species= decrease in reactivity
disproportionation?
a redox reaction in which the same element is both oxidised and reduced
