why can't gravimetric analysis be used to determine the concentration of sodium nitrate (NaNO) in a solution?

I think the answer is because NaNO dissolves in water. Am I correct

I think your answer is the one that the "prof" wants but I might clarify a little.

Yes, NaNO3 is not easily determined both because most Na salts are soluble and most nitrate salts are soluble so there is no easy way to convert them to insoluble forms. Of course you have already pointed out that NaNO3 itself is quite soluble. However, I remember that sodium zinc uranyl acetate is insoluble and I have used that as a QUALITATIVE test for Na many years ago when I was a student. I found an article on the web that explains that under carefully controlled conditions Na can be QUANTITATIVELY determined if the amount to be determined is large enough. I don't have any first hand knowledge of its accuracy but in general I think you are on solid ground that quantitative determinations of Na are not easily done. K is another one of those that is difficult and for the same reasons.

Yes, you are correct. Gravimetric analysis involves the measurement of mass to determine the concentration of an analyte in a solution. However, gravimetric analysis cannot be used to determine the concentration of sodium nitrate (NaNO3) in a solution because NaNO3 readily dissolves in water. Once dissolved, the sodium and nitrate ions separate and become uniformly distributed in the solution. As a result, it is not possible to isolate and collect a specific compound, such as NaNO3, from the solution to measure its mass accurately using gravimetric analysis.

Yes, you are partially correct. Gravimetric analysis involves measuring the mass of a pure compound in order to determine the amount or concentration of another substance present in a sample.

However, in the case of sodium nitrate (NaNO3), it cannot be determined through gravimetric analysis because this compound readily dissolves in water. When sodium nitrate is added to a solution, it dissociates into sodium ions (Na+) and nitrate ions (NO3-), which become uniformly distributed throughout the solution due to the process of solvation.

Since gravimetric analysis relies on isolating the compound of interest as a pure solid substance, it cannot effectively measure sodium nitrate concentration in a solution. The dissolved ions would not precipitate into a solid form that can be easily collected and weighed.

To determine the concentration of sodium nitrate in a solution, you would need to employ a different analytical technique, such as titration or spectroscopy, which are more suitable for analyzing compounds in a liquid state.