[Kryolith]

From there then, i take 0.16 moles from 0.18 moles to give 0.02 moles??? How does that convert to grams?

Sorry I haven't read this. The answer is correct. Conversion to mass is easy: m=M*n

[submar1ney]

Ok guys, here's what i get from a similar example.

Given 12.6g of 2HNO₃ and 15g of CaCO₃, how much CaCO₃ is left after the reaction is over.

2 moles of 2HNO₃=126.02g  and  1 mole of CaCO₃ = 100.1g

100.1 : 164.1 = 15g : x

x = (100.1 / 126.02) x 12.6g = 10g of CaCO₃ left over???

Hope so...

Cheers

[Kryolith]

15g - 10 g (0.1 mol) = 5 g left over...
assuming that you start with 12.6 g HNO₃
if you start with 6.3 g  you are right.

[Borek]

x = (100.1 / 126.02) x 12.6g = 10g of CaCO₃ left over???

Kryolith already gave you the final answer - you made small mistake. You have CORRECTLY calculated mass of calcium carbonate that REACTED. You have just forgot the final step.

[submar1ney]

Ah so what i calculated is the amount used in the reaction?

[Borek]

Ah so what i calculated is the amount used in the reaction?

Exactly

[submar1ney]

Ah so what i calculated is the amount used in the reaction?

Exactly

Ok...  just to clear up my confusion..  hahaha   I calculated the amount of CaCO₃ used in the reaction, so subtract this from the original amount of 15g i'm left with 5g of CaCO₃?

I love chemistry 

[Kryolith]

15g - 10 g (0.1 mol) = 5 g left over...

Congratulation. You got it! 

[submar1ney]

thanks for all your help guys ;-)

Have a good night.

[Mitch]

Very god job all.

5 scooby snacks given to Kryolith, Borek and Alpha-Omega.