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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: WilliamYWT on June 04, 2012, 05:37:29 AM

Title: How to define solute and solvent? (conc. sulphuric acid and conc. nitric acid)
Post by: WilliamYWT on June 04, 2012, 05:37:29 AM

For everywhere I've searched on books and internet, they all said solvent is generally larger in amount than solute. I wonder should I take the word "generally" seriously. And does the word "amount" means its "mass" or "no. of moles/no. of atoms/no. of ions"? Then as I'm learning acid & base. I found conc. HNO₃ contains 65% by mass and conc. H₂SO₄ contains 98% by mass, so I wondered if they are solute because they ionizes or if there isn't really a fine line between solute and solvent.

Title: Re: How to define solute and solvent? (conc. sulphuric acid and conc. nitric acid)
Post by: Schrödinger on June 04, 2012, 06:22:24 AM

Let us say you are able to dissolve 2 g of compound A (solid) in 1 g of a liquid, say water. Now just because mass of A is greater, that doesn't make it the solvent.

Title: Re: How to define solute and solvent? (conc. sulphuric acid and conc. nitric acid)
Post by: Hunter2 on June 04, 2012, 07:29:10 AM

I think its a matter of view. In case of solid substanzes dissolved in a liquid, the liquid is the solvent.

But if you have two liquids it can be both.
In case of your example the acid. 98% H₂SO₄ contains 2% Water and 98% acid by weight.

So the acid can be dissolved in the water, but also the water can be dissolved in the acid.

In most cases if water is used it is the solvent. But in case of organic compounds it can differ.

Title: Re: How to define solute and solvent? (conc. sulphuric acid and conc. nitric acid)
Post by: AWK on June 04, 2012, 08:39:20 AM

Manufacturer selling us a concentrated sulfuric acid informs about its content in solution (at least 98 % but may be more), not about water content.
The water content for most commercial solutions  is not important.