[Histonet] ht exam and formulas

[Lee & Peggy Wenk]

Chemical formula or mathematical formula?

If, on the HT or HTL exam, they ask you how many grams are needed to make a
molar solution - they will provide you with the atomic weight of each atom.
And they will provide you with the formula of the chemical. But they will
NOT provide you with the mathematical formula to solve the equation.

An example might be:
How many grams are needed to make 200 mL of a 0.5 Molar solution of aluminum
hydroxide
Al(OH)3?   Al = 27, O = 16, H = 1.

You would have to know how to figure the molecular weight ((1x27) + (3x16) +
(3x1) = 78).

You would then know the mathematical formula for molar solutions:
g = M x V x MW

And then know how to solve it.

g = 0.5 x (200/1000) x 78 = 7.8 g  (if I figured this correctly)

The same is true for all the lab math formulae (percent solutions,
dilutions, temperature conversion, gravimetric factors, hydrates, etc.).

Peggy A. Wenk, HTL(ASCP)SLS
William Beaumont Hospital
Royal Oak, MI 48073

----- Original Message -----
From: <JCarpenter764 <@t> aol.com>
To: <histonet <@t> lists.utsouthwestern.edu>
Sent: Monday, January 12, 2004 4:34 PM
Subject: [Histonet] ht exam and formulas


> Can someone also tell me wether or not the formulas are provided for
solution
> preparation or not
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