Any body can help??

Why none of metal can dissolve??

 

Metals do react and dissolve in water. Why, some (like potassium and sodium) are sooo reactive, in contact with water, that the reaction is explosive!!

 

For metal, maybe it's because metals are composed of atoms...

 

The metallic lattice, in general, is composed of positively charged atoms (or some would call, 'metal ions') surrounded by a sea of delocalised electrons and it is this electrostatic force of attraction that gets broken by water molecules during hydrolysis.... if I am not wrong.

 

Regards,

mak10

Metals do react and dissolve in water. Why, some (like potassium and sodium) are sooo reactive, in contact with water, that the reaction is explosive!!

well, alkali metals are the anhydrides of their hydroxides. they don't dissolve; they react and become hydroxides, which then dissolve

well, alkali metals are the anhydrides of their hydroxides. they don't dissolve; they react and become hydroxides, which then dissolve

 

My bad... I confused reactivity with solubility. I stand corrected!

 

Regards,

-mak10

"like what?? Glided"

 

Well, you can certainly have a molecule that consists of two gold atoms. And please, call me Gilded. Or G. Or Gil. But not Glided.

Are oxides of metal soluble in water?

thx for you guys....

 

but now I want to know more....

 

I assume that pottasium first having reaction with water, and then dissolve..., but dissolve in what??? Hydrogen are released, I think...

 

Any way, can any one give me a full chemical equation for this??

 

thx

 

Albert

"Are oxides of metal soluble in water?"

 

Don't they become hydroxides when in water? And form an alkaline solution? And non-metal oxides form an acidic solution? No wait, too much mushrooms... Perhaps bud knows something about this.

 

"I assume that pottasium first having reaction with water, and then dissolve..., but dissolve in what??? Hydrogen are released, I think..."

 

"Oh Sir, please take my electron", says potassium. "Right'o", says water, takes the electron and kicks one of its hydrogens away. And as we know, hydrogen is one of those dudes who likes to be with... another dude.

 

(2)Na + (2)H2O --> (2)Na+ + (2)OH- + H2

 

So... hydrogen is released, potassium loses its electron, and OH- are formed. The Na+ and OH- would happily form NaOH, but the evil water molecules separate them. :/ This makes the solution become fairly alkaline when you add 'em alkali metals in it.

K + H2O = KOH + H (and heat).

Are oxides of metal soluble in water?

 

Yes. Oxides of metals are ionic and all ionic compounds are soluble in water.

 

I assume that pottasium first having reaction with water, and then dissolve..., but dissolve in what???

 

Potassium reacts with water, produces potassium hydroxide which 'dissolves' in water... meaning it is present is a dissociated form = K+ and OH- surrrounded by water molecules.

 

the complete chemical equation goes something like:

 

2K(s) + 2H2O(l) = 2KOH(aq) + H2(g)

 

Regards,

mak10

Oh.......

 

It is just the same principle like salt dissolving in water....

 

First K is reacted water OH, form KOH,...

 

and the water molecules overcome the attraction of this ionic bonding, thus the solution conducts electricity... right?

 

By the way, may this question might be a bit off topic, as I see that H2 is gas, why it cant be ionic?? I mean, would'nt if one of the hydrogen looses one electron and the other accepts it, the bonding will be more firm??

 

Albert

Oh.......

 

It is just the same principle like salt dissolving in water....

 

First K is reacted water OH' date=' form KOH,...

 

and the water molecules overcome the attraction of this ionic bonding, thus the solution conducts electricity... right?

 

By the way, may this question might be a bit off topic, as I see that H2 is gas, why it cant be ionic?? I mean, would'nt if one of the hydrogen looses one electron and the other accepts it, the bonding will be more firm??

 

Albert[/quote']

 

 

In regards to the K reaction, you're right! (Though I do have to mention that Aluminum oxide is not soluble in water, so all metal oxides aren't water soluble). Hydrogen is not an ionic compound because the two atoms involved are both hydrogen, so they both have the same pull on the electrons. The electronegativity between the two atoms is exactly the same, so neither of them exhibit a stronger attraction to the electrons. As a result, the electrons are equally shared and the compound is completely non-polar. The same can be said of all diatomic elements.

 

A good thing to remember is that if a compound exists as a liquid or gas at STP, it is not an ionic compound.

Talking of diatomic, does gold occur in nature as diatomic molecules? Or is it just that it CAN occur as diatomic molecules?

So, just for sure

 

Na + + OH-

 

for the above ions, the elctron from Na gives to the Oxygen side, not Hydrogen side, right??

 

because O has more negativity than Hydrogen, that's the reason??

 

Albert

Yeah, the oxygen attracts the electron more, since it's more electronegative.

Hey....

 

I found that electronegativity is a quite major part of chemistry...., because it tells about the bonding the atoms are going to form.... and tells about the relationship between attraction....

 

Can any one give me as good as possible site which gives info about electronegativity and related issue??

 

thx

 

Albert

http://www.chemguide.co.uk/atoms/bonding/electroneg.html

 

-mak10

thx mak!!