What would be the proportion/ratio of zinc metal to hydrochloric acid to make a zinc chloride solution, which in in turn would be evaporated to precipitate zinc chloride crystals?

 

Thanks,

Ken

Zn + 2 HCl → ZnCl2 + H2

 

that should help

So that would be 1 part Zinc to 2 parts Hydrochloric acid? Sorry if I have it way wrong, I'm kind of new at this.

 

Thanks,

Ken

yeah 1mol of zinc will react with 2 mols of hydrochloric acid.

a mole is 6.02x10^23 atoms of ANY element or molecule, for Zinc 1 mol is 65.4 grams, and H=1 and Cl= 35.5 so when you add them you get 36.5 grams for 1 mole of HCl, but you`ll need 2 moles so ya double it to 73 grams.

 

although you`ll not be able to buy pure HCl as it`s a Gas, so you`ll have to factor in the percentage of it in the acid you`re using.

Wow thats a lot of zinc. I am having trouble understanding the measurement of moles. Just to make sure I'm have this right, would I take 2ml of 30% HCl and dissolve 1 gram of zinc in it? Or does the amount change because it's 30% and not 100%?

 

Thanks,

Ken

 

Oh, never mind YT explained it. So what would I have to do to get the amount required for 30% HCl?

it is a lot if you`re planning on making it in whole Molar amounts, but these work right down into nano grams and lower too, it`s just a maths thing.

 

and I`m really crap at maths as anyone (incl myself) will tell you.

 

but your Ratio is 65.4 : 73

 

that`s all I dare say. I`ll ask Insane Alien to do that bit

okay, you have 15(ish)mmol of zinc so you'll need 30(ish)mmol of HCl

 

30mmol of HCl is 1.1g

 

so you'll need 3.7g of the 30% solution (assuming it is weight for weight) to disolve it. this would equate to about 3.7ml call it 4ml to make sure you disolve it all.

So, if I'm doing my math correctly, if I had a 40% solution of HCl instead of 30%, I would need 2.75ml of of it?

 

Thanks,

Ken

yup, that comes up about right when I fiddle with my calculator a bit

i concur. i get 2.75ml as well.

One more thing:

 

okay, you have 15(ish)mmol of zinc so you'll need 30(ish)mmol of HCl

 

How did you get 15mol Zinc and 30mol HCl?

 

Thanks,

Ken

15 mmol. mmol is millimol a thousandth of a normal mol.

 

i don't like working with 0.000XXX numbers so i use the prefixes. it's still SI

 

though i more commonly work with kmols(thosand mols)

So 1.0g Zn = 15mmol?

 

Ken

pretty much. its 1/65.4 to be more exact.

Finally, here is all of my math, hopefully correct:

 

ZnCl2

1 mol Zn -to- 2 mol HCl

 

 

1 mol Zn = 65.4g

1 mol H = 1.0g

1 mol Cl = 35.5g

 

1 mol HCl = 36.5g

2 mol HCl = 73.0g

 

15mmol Zn -to- 30mmol HCl

 

15mmol Zn = 1.0g

30mmol HCl = 1.1g

 

30% HCl = 0.3

 

1.1/0.3 = 3.666 (3.7)

 

3.7g = 3.7ml

 

ZnCl2 = 1.0g Zn -to- 3.7ml 30% HCl

 

Thanks,

Ken

yeah we got there a while ago.

Great! Thank you Insane_Alien and YT for all of your help! I think I have a better understanding of the math behind chemistry now.

 

Ken