Empirical formula... (1 Viewer)

[Aerlinn]

I have trouble with this question:
When 1.66g of tungsten (W) is heated in excess chlorine gas, 3.58g of tungsten chloride is produced. Find the empirical formula of tungsten chloride.

I went a little way and got hopelessly stuck =S

 

[Forbidden.]

(1) Find your masses

1.66 g Tungsten (W)
3.58g - 1.66g of Chloride (Cl) is 1.92g

(2) Mass to moles:

W: 1.66 Mg x (1 mol W/183.9 g W) = 0.009 mol W
Cl: 1.92 g N x (1 mol Cl/35.5 g Cl) = 0.054 mol Cl

(3) Divide by small:

W: 0.009 mol / 0.009 mol = 1.00
Cl: 0.054 mol / 0.009 mol = 6.00 (Divide all with the smallest mole)


Since you already have integers you don't need to multiply them.



Formula of the compound is WCl₆.

 

[Aerlinn]

Ah, thanks. Heh, didn't expect it to be that easy to figure out. Guess I need lots more practice

 

[Forbidden.]

You won't be assessed directly on the Preliminary stuff in the HSC, you are expected to know it, with the exception of Maths ...