Question

Metals + cold water.

Li, Na, K, Ca.

Notes on reactions, equations or space? <<<< don't no what space or equations means. can someone help?
Also, say order of reactivity.

Answer 1

see equation 13.10 for these very active metal reactions.
http://books.google.com/books?id=rGM39e3HqvYC&pg=PA347&lpg=PA347&dq=active+metals++and+water+reactions&source=bl&ots=Q9PjQxytN0&sig=ApQu4us2xNoCfwa87sS1ludGmCE&hl=en&ei=TsO7SfviN4K2NPujlZYI&sa=X&oi=book_result&resnum=8&ct=result

I have no idea what space means here. Equations mean what is the reaction?

Answer 2

Your cryptic question must be clarified if we are to help. Please amplify.

Answer 3

With Li, Na and K the reactions are exothermic [give out heat] and you would see flames and the metals would move vigorously on top of the water.
The reactivity order is Li<Na<K
so K is the most reactive.

The reaction of an alkali metal with water gives a Hydroxide and Hydrogen given off.
Here is the balanced equation for K
2K + 2H2O -> 2KOH + H2
2Na + 2H2O -> 2NaOH + H2
You can do the one for Li now.

For Ca the equation is slightly different as Ca has a valency of 2 so 2 OH- ions can attach which gives
Ca+ 2H2O -> Ca(OH)2 + H2
This reaction is less vigorous than the above metals [unless the water is hot in which case it's very vigorous]

I don't know what 'space' means for this question but I hope the rest has helped.