Hi this is a biochemistry assignment The question is

If 45mg of A (MW 190D) is dissolved in 10 ml of water in a test tube incubated at 23 degrees with an appropriate catalyst until equilibrium is reaches, what is the concentration of F?

I know how to do the problem, but what I am am having a slight problem with is how to get the concentration of A from the information given.. which is 45 mg of A ( MW 190D) dissolved in water. Also Have any one came across MW 190D? If so what does thiss mean? I have searched and could not find it.

I think the MW of 190D must be a typo. Molecular weight is only ever a number.

EDIT

If it is homework just do the calculation assuming the MW is 190 (not an unreasonable number) and maybe write a note saying you didn't understand what the D is about. You'll get the marks for doing the calulation right which is what they are testing anyway.

Q=mc/\T
Q=amount of heat required to cause the temperature change(expressed in calories)

m=mass of material experincing the temperature change(expressed in grams)

c=specific heat capacity, a measurement of the material's ability to retain heat(expressed in cal/g*C)

/\T= the change in the temperatue of the material(expressed in *C

A 500g sample of an unknown material requires 750 calories of heat to raise its temperature by 50*C. solve for c

If 45mg of A (MW 190D) is dissolved in 10 ml of water in a test tube incubated at 23 degrees with an appropriate catalyst until equilibrium is reaches, what is the concentration of F?


I'm pretty sure that means "MW 190 Daltons", though usually they use "Da" and not just "D". A Dalton is the mass of a hydrogen atom, or a proton or a neutron. It's the "atomic mass unit". So, "MW 190D" = Molecular Weight = 190 grams/mole.

Atomic mass unit - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Atomic_mass_unit)

So \frac {45\,mg}{10\,mL} \,\times\, \frac {1\,mmole}{190\,mg} \, = 0.0237\,\frac {mmoles}{mL} = 2.37\times 10^{-2}\, \frac {moles}{Liter}