Reef Chemistry Question of the Day #217 Elements and Specific Gravity

[Randy Holmes-Farley]

Reef Chemistry Question of the Day #217

If I were to add one billion of each of the following ions to a liter of seawater (as, say, the chloride salts), which of them will show the largest increase in the actual specific gravity (i.e., not necessarily what some particular device might measure, but the true specific gravity)?

A. Sodium
B. Potassium
C. Calcium
D. Magnesium
E. Strontium
F. All will be the same

Good luck!










































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[SDReefer]

I'm going to go with C. Calcium.

 

[chefjpaul]

1). Calcium
2). Strontium (close second)
3). Magnesium
4). Sodium
5). Potassium

 

[reeferfoxx]

1 - Strontium
2 - Calcium

Since Strontium and Calcium minerals coprecipitate at higher pH and there are equal parts, would those two be the real impact? Seems like a lot of strontium lol

 

[Randy Holmes-Farley]

1 - Strontium
2 - Calcium

Since Strontium and Calcium minerals coprecipitate at higher pH and there are equal parts, would those two be the real impact? Seems like a lot of strontium lol

FWIW, a billon ions in a liter is hardly noticeable.

 

[JimWelsh]

1 - Strontium
2 - Calcium

Since Strontium and Calcium minerals coprecipitate at higher pH and there are equal parts, would those two be the real impact? Seems like a lot of strontium lol

Well, since there are 6.022 * 10^23 ions in 1 mole, and only 1 billion ions = 1 * 10^9, then we are only adding around 1.66 BILLIONTHS of a MICROMOLE! Hardly "a lot of strontium"! LOL

 

[Randy Holmes-Farley]

FWIW, there are more than 30000000000000000000000000 water molecules in a liter, or 33 million billion billion.

 

[reeferfoxx]

FWIW, a billon ions in a liter is hardly noticeable.

Well, since there are 6.022 * 10^23 ions in 1 mole, and only 1 billion ions = 1 * 10^9, then we are only adding around 1.66 BILLIONTHS of a MICROMOLE! Hardly "a lot of strontium"! LOL

FWIW, there are more than 30000000000000000000000000 water molecules in a liter, or 33 million billion billion.

Thanks! LOL I'm eating my words ;Eggonface

 

[Ryan@ShelteredReef]

E. Strontium

 

[JimWelsh]

I'm looking to the molecular weights of the various chloride salts of these metals for my answer. While the correlation between the molecular weight of a salt and the density of an aqueous solution of that salt of a given molarity is not entirely linear, there is a very strong correlation. Compare the MW of these salts with the density of a 1.0M solution at 20C:

I'm going with "E".

 

[Ryan@ShelteredReef]

I'm looking to the molecular weights of the various chloride salts of these metals for my answer. While the correlation between the molecular weight of a salt and the density of an aqueous solution of that salt of a given molarity is not entirely linear, there is a very strong correlation. Compare the MW of these salts with the density of a 1.0M solution at 20C:

I'm going with "E".

+1

 

[chefjpaul]

I'm looking to the molecular weights of the various chloride salts of these metals for my answer. While the correlation between the molecular weight of a salt and the density of an aqueous solution of that salt of a given molarity is not entirely linear, there is a very strong correlation. Compare the MW of these salts with the density of a 1.0M solution at 20C:

I'm going with "E".

This makes more sense to me now.

 

[reeferfoxx]

I'm looking to the molecular weights of the various chloride salts of these metals for my answer. While the correlation between the molecular weight of a salt and the density of an aqueous solution of that salt of a given molarity is not entirely linear, there is a very strong correlation. Compare the MW of these salts with the density of a 1.0M solution at 20C:

I'm going with "E".

This was interesting to me. You know, I'll admit I'm here to learn. I'd like to side with this but I'm just not finding enough information on SrCl2(strontium chloride). Other than it's a precursor for other Strontium compounds. I think what has really thrown me off is Randy is adding billions of ions of these elements into "seawater". An article from Stanford suggests the concentrations of common/conservative elements of ocean water would normalize to salinity. Therefore being uniformly distributed.

1 - Strontium
2 - Calcium

So, I'm changing my answer to F. All will be the same. (That's my final answer)

 

[JimWelsh]

I'm just not finding enough information on SrCl2(strontium chloride).

Google "crc handbook of chemistry and physics pdf". Chapter 8, in the sub-section titled "CONCENTRATIVE PROPERTIES OF AQUEOUS SOLUTIONS: DENSITY, REFRACTIVE INDEX, FREEZING POINT DEPRESSION, AND VISCOSITY."

 

[Alfrareef]

E.

 

[Ghxst]

E

 

[MnFish1]

Strontium

 

[Saltwaterwannabe]

Strontium

 

[SDReefer]

So is Strontium the correct answer @Randy Holmes-Farley?

 

[Martin Kuhn]

E