Why Does Dissolved NaCl in Water Taste Salty?

[temaire]

Homework Statement

If NaCl dissociates into Na+ and Cl- ions when dissolved in water, why does the solution still taste salty?

Homework Equations

None

The Attempt at a Solution

I think its because a chemical change hasn't happened. Am I right? Can someone go into a bit more detail please?

 

[chemisttree]

Is it possible to taste anhydrous salts (with a moist tongue)?

 

[temaire]

So we can only taste salt when its dissolved in water?

 

[symbolipoint]

You are asking a physiology question. Sodium chloride dissolves and is ionized in water. Taste depends on substances being dissolved when they contact our tongue and its tastebuds. I suspect that olfactory sense works similarly, but maybe our "buds" there need to be at least a little bit moist.

 

[ace123]

Well the people above me are most likely correct but I think the answer is even simpler. Our taste of the salt water depends just on the Na+ ion and Cl- ion being present. They do not have to be in solid form. Thats why we still taste the salt in the salt water.

Also when you put solid salt in your mouth. Your tongue is what?

 

[symbolipoint]

Well the people above me are most likely correct but I think the answer is even simpler. Our taste of the salt water depends just on the Na+ ion and Cl- ion being present. They do not have to be in solid form. Thats why we still taste the salt in the salt water.

Also when you put solid salt in your mouth. Your tongue is what?

We have four tastes and each is detected on a corresponding region of the tongue. Salty taste is detected on a specific region, different from each of the other three regions (being for sweet, bitter, and sour). This is why the original question may really be about physiology. How to account for any particular ions about taste on the tongue -- can't say; and I would not really want to suggest experimenting with this through this online forum (safety problem in case someone does something foolish or dangerous). Chemistry instruction typically and sensibly discourages the tasting of substances

 

[ace123]

LOL. I think you misunderstood me b/c I wasn't doubting your answer at all. In fact I completely agree that its a physiology question. And I know about the different regions...

I think it would be difficult to prove this because of the fact that it's a physiology question. It's like saying what came first the chicken or the egg? But what I was saying was my own thinking. Which may or may not be correct.

 

[chemisttree]

So we can only taste salt when its dissolved in water?

Yes. You don't taste the solid, just that fraction that has dissolved from it.

 

[temaire]

Thanks guys, you've really driven the point hard.