Primary standards question (1 Viewer)

[leehuan]

The question uses crystalline oxalic acid (aka oxalic acid dihydrate) as a primary standard. This comes in the form (COOH)2.2H2O

Apparently, his teacher said to include the 2 H2O in the molar mass for the calculations, while his chem tutor said not to. Which obviously makes a difference in the calculation.

Do you? And why or why not.
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(Once again, please help my friend. thanks.)

 

[1008]

Well I guess if crystalline oxalic acid (just (COOH)2 without the hydrates) was used, adding it to water to get those extra dihydrates shouldn't impact the experimental results, so I think he shouldn't include it in his calculations. Because, according to me, adding the oxalic acid to the water just causes the acid to essentially dissolve in the water and pick up that dihydrate (similar to changing from a solid to aqueous subscript) and so it should be treated as just a change of state.

But I'm not completely sure.

 

[leehuan]

^Yep cool makes sense

Anyone want to back this up?