1. Reaction of alkali metals with water

2. 2) Today you will learn:
1) Do and describe an experiment in which an alkali metal reacts with water
2) Write an equation of this reaction
3) Name the product and explain the change of colour and the reason for ignition
4) Compare the reactivity and ionization energy of sodium and potassium

3. 3) Alkali metals name as many alkali metals as you know (as a class)
talk about properties of the alkali metals (work in pairs,
speak, take turns)
Common properties
The alkali metals have the following properties in common:
they have low melting and boiling points compared to most other metals
they are very soft and can be cut easily with a knife
they have low densities (lithium, sodium and potassium will float on water)
they react quickly with water, producing hydroxides and hydrogen gas
their hydroxides and oxides dissolve in water to form alkaline solutions

4. 4a) Do you understand these phrases?
In pairs explain the key words:
remove a piece of potassium
a gray coating of the oxide
the shiny metal surface
consistency of cream cheese
react rapidly
to turn red purple
Exothermic
to add phenolphthalein

5. 4b) What do these pictures represent?

6. 4c)
phenolphtalein
shiny metal surface
cream cheese
exotermic

7. 5) video Watch and listen. Write down the key words as you hear them

8. 6) Choose one of the two possibilities:
1) Do the following experiment:
- prepare a knife, a cutting board, tweezers, and a beaker
- remove a small piece of sodium
- put the metal into the beaker with water
- observe the reaction
2) Watch the video on

9. 7) You can watch
Link to useful websites

10. 8) Useful phrases increase decrease metal reactivity ionization energy
alkalinity
product ignites
get softer and softer
indicator

11. 9) Useful phrases Sequencing words:
First(ly), Second(ly), Third(ly), Then, Next, After that, Finally, …
Describing steps in a chemical experiment:
to remove, to take, to cut, to pour, to put, to add, to prove, to turn red, to ignite,
Describing process:
In order to do this, we need to… To do this, we need a …
Comparing and contrasting:
… is not as …., … is –er than …., … is (not) the same as …., … is much greater/smaller/faster/…. than …., … is different from …. ,
…. but ….., …..However, ….. , …. in comparison with ….,

12. 10) Assesment criteria
clarity and correctness of description of the experiment
correctness of the equation
justification of the presence of products
clear explanation of the similarities and differences of the two experiments
effective use of language

13. Email addresses: dagmar.sanderova@mssch.cz dagmar.kohoutova@mssch.cz