[BaO]

how can i determine which one is more conductivity in a list of equal concentration compounds( salts, acids ,and bases)
all i know is the stronger an acid is , the more conductivity.what else should i know?

thanks in advance

[Mitch]

You would have to compare the solubilty constants for salts an disociation constants for acids and bases.

[Borek]

That's not all, as different ions have different conductivities, which you should take into account. If you take 0.01M HCl and 0.01M NaCl solutions the latter will have lower conductivity, although both solutions contain same number of ions. 0.01M NaOH solution will have conductivity smaller than HCl, but higher than NaCl solution - and so on. Individual ion conductivities are tabularized and you may find them in handbooks.

[BaO]

could you help me out on this question?
 
a student titrates 25.0mL of 0.100 M Ba(OH)₂ with 0.100M H₂SO₄.what happens to the conductivity of Ba(OH)2 solution as the first few mL of H₂SO₄ are added?
anothe one is what happens to the conductivity if extra H₂SO₄ is added after the equivalence point is reached?

 there are some more questions but i think i got them , only the above questions i dont really get

thank you very much
 

[Borek]

What do you think? What happens in the solution?

[BaO]

for the first question , i think more ppt will be formed( BaSO4), and results in an decrease of [Ba]and [OH],  so the conductivity of Ba(OH)2 decreases?

the second one, i guess the conductivity will not change . i dont know,
 my problem in this question is: i dont know what the equivalence point is ! even though i have read throughout the book several times!

[Yggdrasil]

i dont know what the equivalence point is ! even though i have read through the book several times!

When titrating a base with an acid, the equivalence point is when the number of moles of H⁺ added equals the number of moles of OH^- originally in solution.  In other words, the equivalence point occurs when the acid has reacted completely with the base.

[BaO]

yeah, i know when it's reached, but it seems still weird to me
does it mean no more acid can react with the base and vice versa at the equivalence point?

what about other questions?

[Borek]

Think about titration stoichiometry - at first you have solution of strong base, thus there are two ions (Ba²⁺ and OH^-) resonsible for conductivity. If you add some sulfuric acid two reactions occur - removing these ions (what reactions am I referring to?). When amount of acid added (in terms of numbers of moles) is identical to initial amount of base you have (almost) pure water. What happens next?

[BaO]

um.. i'm just wondering if you did read my answer above. just in case, i send it again .anyway , i'll think about your suggestion and then i will reply it

for the first question , i think more ppt will be formed( BaSO4), and results in an decrease of [Ba]and [OH],  so the conductivity of Ba(OH)2 decreases?

the second one, i guess the conductivity will not change (after decreasing).

[BaO]

When amount of acid added (in terms of numbers of moles) is identical to initial amount of base you have (almost) pure water.

and salt?

[Borek]

When amount of acid added (in terms of numbers of moles) is identical to initial amount of base you have (almost) pure water.

and salt?

Not in this case - BaSO₄ was removed from the solution as precipitate. But in general you are right, solution at equivalence point should contain just salt.

[BaO]

what about the questions? you  dont forget about them , do you?
i just read the second question again , and i realized that it asks about the conductivity of the solution. you think so ? and when some extra H2SO4 is added , there will be more ions (H⁺, SO₄^-2) so .. i'm not sure. will that affect the conductivity?

[Borek]

there will be more ions (H⁺, SO₄^-2) so ..

Right!

i'm not sure. will that affect the conductivity?

But you've killed me here... You start with almost pure water (BaSO₄ lies on the bottom), you add strong acid and you wonder how it will change conductivity?

there are some more questions but i think i got them , only the above questions i dont really get

If you have such basic doubts, I doubt you were able to answer correctly other questions.

How does the solution conduct electric current?

[BaO]

i was just not sure!  
the conductivity at the time will increase?(for second question)

one more thing : at the equivalent point there will be any ion? i guess not right? and therefore, the conductivity is almost 0? am i on the right way?

hey ,just now i realize that we should also base on ions to consider the conductivity , right?
and just to let you know i did the other questions correctly, this time i am sure ! they are calculating questions. i'm not an expert in chemistry but dont underestimate me like that