6.1 Group 1 Flashcards
What is the other name for group 1 elements?
Alkali metals
Name the elements in group 1 (lightest to heaviest)
Lithium (Li)
Sodium (Na)
Potassium (K)
Rubidium (Rb)
Caesium (Cs)
Francium (Fr)
What are the features of alkali metals? (Four)
Slivery solids
Need to be stored in oil and handled with forceps (as they are very reactive)
Low melting and boiling points
Soft (can be cut with a knife)
How do group 1 metals react?
They lose their outer electron
Why are larger group 1 metals more reactive?
The outer electron gets further away from the nucleus the larger the element is, so it is easier to lose it (less attraction from the nucleus)
This creates a metal ion (so alkali metals only form ionic compounds)
Write the general word equation for the reaction of an alkali metal with water,
Alkali metal + water -> metal hydroxide + hydrogen
Write a balanced equation for the reaction of potassium and water
2K (s) + 2H2O (l) –> 2KOH (aq) + H2 (g)
s = solid
l = liquid
aq = aqueous (in solution)
g = gas
Why are group 1 metals called alkali metals?
Because they react with water to give alkaline solutions
Describe what you will see when a group 1 metal is added to water.
How do you test for the pH of the solution and the gase being produced?
The metal will whizz along the surface of the water, and fizz due to bubbles of hydrogen being produced.
Solution: turns universal indicator purpule (alkaline)
Gas: when a lighted splint is put to it, it will make a squaeky pop sound (hydrogen burning)
When reacting with water, what differences are seen with lithium, sodium and potassium?
Lithium: moves on the water and fizzes, but maintains it shape
Sodium: also melts into a ball shape, due to the heat of the reaction
Potassium: melts into a ball AND is hot enough to ignite the hydrogen being produced (lilac coloured flame is seen)
