Group 1 Alkali Metals

Question 1

What group are the alkali metals?

Answer 1

group 1

Question 2

What are elements are alkali metals?

Answer 2

lithium, sodium, potassium, rubidium, caesium, francium

Question 3

What do alkali metals do when exposed to air?

Answer 3

they tarnish and form oxides on the surface.

the rate of tarnishing increases as you go down the group

Question 4

What happens to the reactivity as you go down the group?

Answer 4

the reactivity increases as you go down the group as the atoms get larger. therefore the distance between the outermost valence electrons and the nucleus increases - making the force of attraction weaker. so the valence electrons are more easily lost and to be reacted.

Question 5

What is produced when alkali metals react with water?

Answer 5

they produce heat (exothermic), hydrogen gas and their respective metal hydroxide. the heat in the reaction may ignite a fire/explosion (more reactive elements)

Question 6

What are the metal hydroxides formed with the alkali metals?

Answer 6

lithium hydroxide, sodium hydroxide and potassium hydroxide

Question 7

What type of reaction is the alkali metals and water?

Answer 7

exothermic - release heat

Question 8

Describe the trends of the properties as you go down the group

Answer 8

levels of alkalinity increase down the group

levels of reactivity increase down the group

melting and boiling points increase down the group

atomic size increases down the group (weaker attractions)

Question 9

What are the pH of the solutions after the reaction between alkali metals and water?

Answer 9

all alkali metals produce alkaline solutions - therefore the pH must be over 7. so it would be blue (different shades)

Question 10

Describe some of the observations during the reactions of alkali metals in water

Answer 10

fizzing, igniting, moving, floating

become more vigorous as you go down the group - can use this trend to predict francium (too dangerous to do)