# A mol question

1. Apr 13, 2005

### gordda

how do you work out the amount of mole Chlorine ions in 13.4g of nickel chloride(NiCl2). i don't know how to use the n=m/M with ions?

2. Apr 13, 2005

### ShawnD

$$(mass NiCl_2)(\frac{1 mole NiCl_2}{grams NiCl_2})(\frac{moles Cl}{moles NiCl2})$$

put some values into the equation and everything should work out.
I really wish Latex understood what a space bar does.

3. Apr 13, 2005

### The Bob

$$(mass \ NiCl_2)(\frac{1 \ mole \ NiCl_2}{grams \ NiCl_2})(\frac{moles \ Cl}{moles \ NiCl2})$$

Try adding \ in between the words you want seperating.

Back to the question. Personally (maybe because my knowledge of equations is not as great as some) I would find the percentage of chlorine in the coumpound by using the molar mass of the coumpound and the two elements in it. Then I would find the mass of chlorine (using the percentage) and then find how many moles that was by dividing by the molar mass of chlorine.

Last edited: Apr 13, 2005
4. Apr 15, 2005

### atomicblast

Whenever it comes to calculating moles, mass, molarity etc. always use units as a guide. What you have now is 13.4g NiCl2, and how to convert from g to moles.

From the periodic table, you can calculate the molar mass of NiCl2 to get 1 mol / ?g NiCl2. Also, how many moles of Cl are there in 1 mol of NiCl2?

13.4g NiCl2 x 1mol NiCl2 / ?g NiCl2 x ?mol Cl / 1mol NiCl2 = no of mol Cl

Hope this helps!