Chemistry-Mole

[Night-Shade]

Can anyone help me with the mole chapter or give me some notes.I know a little basics like empirical formula ,molecular formula and percentage composition but I mix all my concepts and understandings.I would appreciate any help.

 

[ahmadumar]

Its not that much hard

 

[Night-Shade]

Its not that much hard

Maybe for u but I have just started the chapter and is kind of confusing.can u tell me how to find empirical formula if the percentage of the elements is given

 

[ahmadumar]

Maybe for u but I have just started the chapter and is kind of confusing.can u tell me how to find empirical formula if the percentage of the elements is given

yeah! just simply divide the percentage of an element by Ar of that paritcular element

 

[ahmadumar]

do the same for the rest of the elements

 

[ahmadumar]

then divide all the answers with the smallest answer you get
get it??
feel free to ask anything

 

[Night-Shade]

then divide all the answers with the smallest answer you get
get it??
feel free to ask anything

thanks,that concept is clear but still what is "dm3" and how to find it if the mass of an element is given

 

[ahmadumar]

thanks,that concept is clear but still what is "dm3" and how to find it if the mass of an element is given

In chemistry we use dm3 as a unit for gases & also liquids...like we use cm3 for liquids, etc. In chemistry 1dm3=1000cm3
therfore, whenever a question gives you volume of gas or liquid, the firs thing is to convert cm3 into dm3 by dividing it with 1000.
Then, using the mole formula, which is only for gases, divide the volume of gas(dm3) by 24(dm3) and you'll get the no. of moles.

Actually, in chemistry, if one mole of each gas is taken at r.t.p. , all the gases will occupy 1 dm3.

And if you are given mass of a substance, first make sure that you convert the mass into grams(g). Then, if the substance is a molecule divide the mass in grams of that substance by its molecular mass. And, if the substance is an atom(e.g Ca , Na etc) divide mass by atomic mass.



P.S: Remember that few elements such as, Iodine, Oxygen, Nitrogen, Hydrogen and a few more exist as diatomic molecules

 

[robinhoodmustafa]

Can anyone help me with the mole chapter or give me some notes.I know a little basics like empirical formula ,molecular formula and percentage composition but I mix all my concepts and understandings.I would appreciate any help.

http://www.mediafire.com/?kwuxd7155olcpay,8yli38v3ybyuud7

 

[Minato112]

thanks,that concept is clear but still what is "dm3" and how to find it if the mass of an element is given

1 dm3 -----> 1000 cm3.

As for how to find the mass, additional informations must be supplied. If U dont mind giving them, we can try to clear your doubt.

 

[ayesh.]

hi, u can get help with ur moles if u mail at [email protected]

 

[ahmadumar]

Maybe for u but I have just started the chapter and is kind of confusing.can u tell me how to find empirical formula if the percentage of the elements is given

so was evrythng of any help or not ?

 

[Night-Shade]

so was evrythng of any help or not ?

It was actually Thanks alot

 

[ahmadumar]

It was actually Thanks alot

Thnx God!
np