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Ask me for chemistry help! (1 Viewer)

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Dylanamali

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kittyful said:
So does that mean that the end conc. will be higher than expected ?

:D
Click to expand...
Kitty also note.. that a somewhat difficult question they ask, is why the conical flask containing the unknown solution is rinsed with distilled water and not the solution it is going to contain. This is because the only thing that matters is the no. of mols of unknown that is in the flask - that is, the concentration becomes irrelevant as a titration is just determining the equilavence pt - which is the pt where there are equal number of mols of OH- and H+. So as long as you have the known number of mols it is okay.
 
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kittyful

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MagnificentOne said:
I've got a question for you guys.
Is Sodium carbonate acidic, basic or neutral? Explain. Use equations.
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Sodium carbonate is basic. Because it contains a conjugate acid of a strong base and CO3 is a conjugage base of a weak acid .

and err i don't have an equation for this
 
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Dylanamali said:
Kitty also note.. that a somewhat difficult question they ask, is why the conical flask containing the unknown solution is rinsed with distilled water and not the solution it is going to contain. This is because the only thing that matters is the no. of mols of unknown that is in the flask - that is, the concentration becomes irrelevant as a titration is just determining the equilavence pt - which is the pt where there are equal number of mols of OH- and H+. So as long as you have the known number of mols it is okay.
Click to expand...
Thanks :D
 
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mangoz

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kittyful said:
Sodium carbonate is basic. Because it contains a conjugate acid of a strong base and CO3 is a conjugage base of a weak acid .

and err i don't have an equation for this
Click to expand...
Just react it with water lol
 
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Dylanamali

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mangoz said:
Just react it with water lol
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hmm, if you react it with a water, it should act as a bronsted lowry base, accepting a proton. That is:

Na2CO3 + H2O -> Na2HCO3+ + OH-

Is that product - sodium hydrogen carbonate, if so, isn't that substance amphiprotic? Just a side note, isn't it strange that a basic substance ionises to form a amphiprotic substance. =/
 
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Dylanamali

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kittyful said:
How would you draw dilute HCL ?
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dilute HCl:

HCl is a strong acid, meaning that it is completely ionised, that means you have to draw only H+ and Cl- ions (NO HCl molecular ions!!)

If it is dilute, that just means you don't draw many of the ions e.g. in a strong you'd draw many H+ and Cl- ions, in dilute you draw few..
 
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kittyful

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Dylanamali said:
dilute HCl:

HCl is a strong acid, meaning that it is completely ionised, that means you have to draw only H+ and Cl- ions (NO HCl molecular ions!!)

If it is dilute, that just means you don't draw many of the ions e.g. in a strong you'd draw many H+ and Cl- ions, in dilute you draw few..
Click to expand...
oh right thanks :D
 
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