What's that term. (1 Viewer)

[jamesfirst]

When the compound does not attract water.


Like Na2CO3 does not attract water and is used in titration...

 

[kfnmpah]

Hydrophobic?

EDIT: NO!

Hygrocscopic?

 

[Squishxmishyx]

Anhydrous or hydrophobic

 

[kfnmpah]

Anhydrous or hydrophobic

I know hydrophobic means "water hating" but that's different to what OP means.

When making a standard solution, you need to choose a chemical compound that is NOT hygroscopic which means it absorbs water from solution and the atmosphere. (different to hydrophobic)
The term OP is looking for is anhygroscopic.

 

[_deloso]

i thought Na2CO3 attracts water... therefore it is a hygroscopic.. cos during titration, na2co3 was covered so that moisture cannot be attracted to it.. cos if it was open then moisture can get attracted to it and stuff up your concentration calculation.

 

[jamesfirst]

Hygrocscopic?

This was the word I was looking for!

Yay. Now I'm gonna get a band 6 in chemistry

 

[jamesfirst]

i thought Na2CO3 attracts water... therefore it is a hygroscopic.. cos during titration, na2co3 was covered so that moisture cannot be attracted to it.. cos if it was open then moisture can get attracted to it and stuff up your concentration calculation.

i thought since Na2co3 is hygroscopic, it was used instead of NaOH which attracts moist around the room...

 

[jamesfirst]

Ah. Hygroscopic means water attracting i see....

 

[b3kh1t]

Do you mean that since Na2CO3 does not absorb moisture from the air (also as it has a high molar mass) it makes a good primary standard, whereas other compounds such as NaOH are not good primary standards as they absorb moisture from air.

 

[jamesfirst]

Do you mean that since Na2CO3 does not absorb moisture from the air (also as it has a high molar mass) it makes a good primary standard, whereas other compounds such as NaOH are not good primary standards as they absorb moisture from air.

yes. sorry


haven't revised it before posting this


so Na2CO3 will be non-hygroscopic while NaOH will be hygroscopic

 

[b3kh1t]

yes. sorry


haven't revised it before posting this


so Na2CO3 will be non-hygroscopic while NaOH will be hygroscopic

Yes Na2CO3 is non-hydrscopic while NaOH is, this is why a primary standard is needed to standardise solutions oh NaOH and this standard solution may be used to titrate other solutions.
Just some extra information, Na2CO3 can come in two forms, anhydrous meaning it does not contain any water, this form will not react as readily if at all with the moisture within the air, and the other form is a hydrated Na2CO3 with 10 H20, so , (information is in the industrial chemistry option topic) both are still non-hydroscopic though.