chem trends in chemical properties Flashcards
chemical properties
determined by valence electrons
group 1 lithium
-least reactive
-keeps shape
-LiOH and H2 (aq)
group 1 sodium
-reacts vigorously
-heat produced
-ball forms
-NaOH and H2 aq
group 18
-noble gases
-effective charge of zero
-least reactive
group 1
-alkali metals
-stored in oil to prevent reaction with water and air
-too reactive to be found in elemental state
-REACTIVITY INCREASES DOWN A GROUP
-form ionic comp with non metals
-conductors of heat and electricity (due to mobility of outer e)
-low density
-shiny grey surface
group 1 potassium
-most reactive
-heat produce
-gas that can ignite H2 gas=lilac flame
-KOH and H2 aq
difference between alkali and alkaline
“alkaline” is like saying something is generally basic, and “alkali” is a more specific term for certain substances that not only are basic but also dissolve in water to make it basic.
volatility
tendency of a sub to vaporize or turn into a gas
identify the prop that causes diff in volatility?
numb of e in halogen molecule
group 17
-halogens
-diatomic
-coloured
-very reactive
-they form both ionic and covalent bonds because they are non metals
-REACTIVITY INCREASES UP THE GROUP
-high effective charge
-good oxisìdising agents
by what are trends in reactivity defined?
by the readiness to accept e
displacement reactions
to determine relative reactivity we can place halogens in direct competition for the extra e
-only the more reactive element can displace
Zn (s) + 2HCl (aq)→ZnCl2(aq) + H2(g)
halides
a halogen ion or a binary compound with a halogen
what technique can be used to easily identify halides?
adding to a solution containing a halide a solution containing silver ions, this produces a precipitate that is useful to identify the halide ion
Ag+(aq) + X-(aq) = AgX
