[alt-photo] Re: platinum

[Alberto Novo]

> Muriatic acid is 37% here in the US and is very inexpensive. It can be found
> at many hardware stores and home care centers such as Lowes and Home Depot
> to name a couple.

Thank you, Don. 

So, 40 cc/L of 37% HCl (d=1.186 kg/dm3) is about 40*1.186*0.37 = 17.55 g/L.
If I have to use 10%, d=1.05, that become 17.55/0.1/1.05 = 167 cc/L.
So written, it seems a fairly high amount. But... 

Further math for calcium carbonate content accordingly with ISO 9706 (at 
least 2%):
1 sheet (56x76 cm) of 300 g/m2 paper has a CaCO3 content of
0.56*0.76*2/100 = 2.55 g 

1 g of CaCO3 is neutralized by 36.456/50 = 0.7293 g of HCl.
This last is in 0.7293/0.37/1.186 = 1.662 cc of HCl 37% 

The CaCO3 of 1 sheet of paper as above is neutralized by (at least)
2.55*1.662 = 4.243973565 cc 

Finally, 10 sheets will require about (at least...) 45 cc of 37% HCl.
I'd say that the amount used by Marek (2 L water plus 80 cc HCL for 6-10 
sheets) is about double than required, but he surely removed all the buffer 
from his papers. 

Alberto 

 

 

 

Alberto
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