Chemistry - repost
posted by candy on .
Why 7ml of 10M HCl? Do I add 7ml of 10M HCl 1st slowly in ice bath, then slowly adjust the pH to 7 using 10M HCl? Then to dilute to 15ml in a graduated cylinder?
Posted by candy on Tuesday, September 21, 2010 at 10:03am.
The following is part of a procedure for a limit test for sulphates in an NaOH sample:-
Dissolve 3.0g of NaOH in 6ml of deionized water, adjust to pH 7 with HCl (approx.7.5ml) and dilute to 15ml with deionized water.
Please explain how to perform this procedure. Conc HCl or 1M HCl? I do not understand it.
Chemistry - urgent - bobpursley, Tuesday, September 21, 2010 at 10:09am
What form of NaOH did you use? Assume granular.
moles HCl needed= 3/40=volume*Molarity
so lets see what 7 ml will neutralize
molarity=3/40/.007= or about 10Molar. 32Percent HCl is about 10M