Group 1 - Alkali Metals Flashcards
(16 cards)
What physical properties do the alkali metals have that makes them similar?
- melting points (similar -ish)
* density
what is the trend of melting points down the group?
The melting point decreases. (the strength of the metallic bonds decrease down the group.)
Which of the Alkali metals will float on water?
lithium, sodium, potasium ( density less than one/water )
Exactly why are the alkali metals similar to each other?
All group 1 metals have a similar metallic bond and chemically all have 1e- in their outer shells
What are the observations of lithium when it reacts with water?
- floats on the surface, skates around
- will disappear
- effervescence
- colourless gas given off
- colourless solution forms
What is the word equation for lithiums reaction in water?
lithium + water = lithium hydroxide + hydrogen
2Li (s) + 2H2O (l) = 2LiOH (aq) + H2 (g)
What are the observations of sodium when it reacts with water?
- floats on the surface, skates around
- solid disappears
- melts into a ball
- effervescence
- colourless gas given off
- colourless solution forms
What is the word equation for sodium reaction in water?
sodium + water = sodium hydroxide + hydrogen
2Na (s) + 2H2O (l) = 2NaOH (aq) + H2 (g)
What are the observations for potassium when it reacts with water?
- ignited with contact with water
- burns with a lilac flame
- crackles at the end
- floats on the surface, skates around
- solid disappears
- melts into a ball
- effervescence
- colourless gas given off
- colourless solution forms
What is the word equation for potassiums reaction in water?
potassium + water = potassium hydroxide + hydrogen
2K (s) + 2H20 (l) = 2KOH (aq) + H2 (g)
What are the observations for rubidium when it reacts with water?
- ignited with contact with water
- violent explosion
- effervescence
- colourless gas given off
- disappears
What is the word equation for rubidiums reaction in water?
rubidium + water = rubidium hydroxide + hydrogen
2Rb (s) + 2H20 (l) = 2RbOH (aq) + H2 (g)
What is the trend in reactivity down group 1?
down the group the reactivity increases
The alkali metals are more reactive down the group because …
group 1 metals react by LOSING THIER ELECTRONS.
- down the group the outer electron gets one shell further away from the nucleus each time
- attraction from the nucleus for outer electron decreases
- hence, electron is removed more easily… It is therefore more reactive
What are some observations about the reaction between sodium and chlorine?
- ignited with a sodium yellow flame
- melted into ball
- when we stopped heating it it still stayed alight for a bit.
- then cloudy white smoke was produced, a salt
- the salt was called sodium chloride
- white solid settles
What is the word equation for the reaction between sodium and chlorine?
Sodium + chlorine = sodium chlorine
2Na (s) + Cl2 (g) = 2NaCl (s)
