-----Original Message-----
From:	Jennings-Siena, Debbie [mailto:ds.jennings-siena@baylordallas.edu]
<mailto:[mailto:ds.jennings-siena@baylordallas.edu]> 
Sent:	Friday, February 11, 2000 6:16 PM
To:	'histonet@pathology.swmed.edu'
Subject:	My brain is fried and I need help

Ok everyone,
You can laugh at me later but I really need your help with this math
question.   I need to make up a 0.2N solution of HCL.  Our HCL is 36.6 to
38% and the FW is 36.46.  Help please.
Debbie J. Siena
The "concentrated hydrochloric acid" sold by chemical companies is 12 N
(really somewhere between 11.8 N and 12.2 N).
0.2 is one sixtieth of 12.  Thus 1 ml concentrated hydrochloric acid plus 59
ml water is a 0.2 N.  If you need a lot of 0.2 N hydrochloric acid, you can
add 16.5 ml of concentrated hydrochloric acid to 983.5 ml water (or add
enough water to 16.5 ml concentrated hydrochloric acid to make 1 liter of
total solution).
Shugar & Ballinger [Chemical Technician's Ready Reference Handbook,
McGraw-Hill, 1990] say to use 16.4 ml concentrated hydrochloric acid for 1
liter of 0.2 N.  This is true only if you have a new bottle of the stuff.
			Allen A. Smith
			School of Graduate Medical Sciences
			Barry University
			Miami Shores, FL  33161