Can't Judge a Powder B

[melody2k6]

Sorry. Did anyone understand the question about the rotten egg odor? My partner and I had no idea what it meant.

I think My partner and I did.
It was the Feric something (brownish color) that had the rotten egg odor

Did it ask for something else though? I thought the question asked something about another observation we can make about Ferric Nitrate (I think. Not sure though)

[frogzorz]

Hmm. My partner and I concluded that it was the sodium sulfide. After all, sodium sulfide (Na2S) contains 2 molecules of sulfur, even in its hydrate form. Both the compound and its hydrate emit hydrogen sulfide, which smells like rotten eggs.
BTW, what the heck is ferric acid? The reactioms to it were similar to HCl except for a few.

[starpug]

Hmm. My partner and I concluded that it was the sodium sulfide. After all, sodium sulfide (Na2S) contains 2 molecules of sulfur, even in its hydrate form. Both the compound and its hydrate emit hydrogen sulfide, which smells like rotten eggs.
BTW, what the heck is ferric acid? The reactioms to it were similar to HCl except for a few.

How does Sodium Sulfide have 2 molecules of sulfur when the charge on sulfur anion is -2 and the charge on the sodium cation is +1.

[rocketman1555]

Hmm. My partner and I concluded that it was the sodium sulfide. After all, sodium sulfide (Na2S) contains 2 molecules of sulfur, even in its hydrate form. Both the compound and its hydrate emit hydrogen sulfide, which smells like rotten eggs.
BTW, what the heck is ferric acid? The reactioms to it were similar to HCl except for a few.

Sodium sulfide only has one molecule of sulfur, it has two molecules of sodium though.

And Ferric Acid is a weak acid, I don't know much else about it though.

[frogzorz]

Oops. My bad. I thought it had two sulfur molecules. I hate my partner!!
A weak acid? We tested for a pH of 1 or 2.

[frogzorz]

Hmm. My partner and I concluded that it was the sodium sulfide. After all, sodium sulfide (Na2S) contains 2 molecules of sulfur, even in its hydrate form. Both the compound and its hydrate emit hydrogen sulfide, which smells like rotten eggs.
BTW, what the heck is ferric acid? The reactioms to it were similar to HCl except for a few.

How does Sodium Sulfide have 2 molecules of sulfur when the charge on sulfur anion is -2 and the charge on the sodium cation is +1.

Yeah, my partner didn't really explain to me the anion or the cation charges for Na2S. Or ichaelm.

[starpug]

Oops. My bad. I thought it had two sulfur molecules. I hate my partner!!
A weak acid? We tested for a pH of 1 or 2.

It's a common mistake

Also the term "weak acid" doesn't mean it can't have a ph of 1 or 2. pH is a measure of H+ ion concentration, so a saturated solution of say citric acid (what makes lemons so sour) can have a pH as low as or lower then a dilute solution of HCl. What makes HCl and other strong acids strong is that they completely dissociate in water so if you were to add the same number of moles of HCl and citric acid to water, the HCl would have the higher pH. The HCl would donate more H+ ions to the solution then the citric acid (making more Hydronium Ions, but the difference between H+ and H30+ is irrelvant to what I'm saying.) which makes the pH lower (they're inversely proportional since pH is the -log[H+]). Even among weak acids, some are stronger then others because some dissociate better then others. Also, pH paper has a history of being unreliable, so it's possible that was a faulty reading.

Ferric Acid's formula H2FeO4, I can't seem to find it's dissociation constant so I don't know how strong of a weak acid it is.

[haven chuck]

Sorry. Did anyone understand the question about the rotten egg odor? My partner and I had no idea what it meant.

I think My partner and I did.
It was the Feric something (brownish color) that had the rotten egg odor

Did it ask for something else though? I thought the question asked something about another observation we can make about Ferric Nitrate (I think. Not sure though)

Yeah, the question was like "Besides a rotten egg odor, what did you observe when ferric nitrate was mixed with the powder". We figured they just wanted a solubility observation

[melody2k6]

Oops. My bad. I thought it had two sulfur molecules. I hate my partner!!
A weak acid? We tested for a pH of 1 or 2.

It's a common mistake

Also the term "weak acid" doesn't mean it can't have a ph of 1 or 2. pH is a measure of H+ ion concentration, so a saturated solution of say citric acid (what makes lemons so sour) can have a pH as low as or lower then a dilute solution of HCl. What makes HCl and other strong acids strong is that they completely dissociate in water so if you were to add the same number of moles of HCl and citric acid to water, the HCl would have the higher pH. The HCl would donate more H+ ions to the solution then the citric acid (making more Hydronium Ions, but the difference between H+ and H30+ is irrelvant to what I'm saying.) which makes the pH lower (they're inversely proportional since pH is the -log[H+]). Even among weak acids, some are stronger then others because some dissociate better then others. Also, pH paper has a history of being unreliable, so it's possible that was a faulty reading.

Ferric Acid's formula H2FeO4, I can't seem to find it's dissociation constant so I don't know how strong of a weak acid it is.

I have always thought a weak acid meant an acid with a pH close to neutral. When my partner and I tested the pH of Ferric Acid (or whatever it is) we got a pH of 4. Would that be considered a weak acid?

[melody2k6]

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