user11841: I am asking this question with regards to this question:
https://biology.stackexchange.com/questions/31510/why-are-the-palms-of-hand-salty
I am agreeing heads on that the data provided has not been recorded in any scientific literature (I am not able to find any). However it is easily verifiable by everyone and if false could be pointed out after which the question can be closed as false data.
However, the people who voted to close the question gave a very interesting reason:

put on hold as primarily opinion-based by GriffinEvo, poka.nandor, WYSIWYG, March Ho, Luigi 11 hours ago
Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise.
If this question can be reworded to fit the rules in the help center, please edit your question.

I was thinking that good question which do not have an answer as of now are not closed. This is what the moderator said in one of his comments here:
Suggest expanding Biology's scope

@OneFace The fact that the answer isn't known yet is not a reason to close a question. –  Mad Scientist♦

Infact there were 4 people who upvoted this comment showing they agree with this idea. But my question got closed. Please explain how some questions with no answer as of yet are kept open while others are closed.
I was of the idea that opinion based close reason are for questions that are opinion based!

user10456: In addition to the reason provided by poka.nandor, my personal take on the matter is that it seems to be the case that the issue of salty palms itself does not appear to be universally applicable. If only a small fraction of people have salty palms, and the problem of salty palms does not appear to be a medically significant problem, there is unlikely to be any significant research done to quantify the issue, unlike the questions given as an example here in this thread, which seem to be areas of active research within well-defined fields. 
Therefore, it is unlikely to be the case that any decent citable research is likely to be done on this topic in the near future, and therefore any answer is likely to be opinion based in the forseeable future. 

user14735: In my interpretation this reason means that the question cannot be answered by scientifically proven fact(s) (basically this is written in the explanation), a thing that this site want to avoid. The question itself may not be opinion based, but the answers it generates would be, and that is the real reason for closure. The question itself is interesting on its own, but I don't remember feeling difference in the saltiness of my own sweat from different parts of my body, although I haven't licked myself too much... As AliceD pointed out in the comments it's quite a gray area.
How it is determined if the question would generate opinion based question? I think when the question is clear enough to get the point (so we know what the OP wants to find out), but it is either based on anecdotal (personal) evidence, or there is no literature at all, is when this type of reason is chosen. There are people here with more routine, may can provide a better answer.

11841: <p>I am asking this question with regards to this question:</p>
<p><a href="https://biology.stackexchange.com/questions/31510/why-are-the-palms-of-hand-salty">https://biology.stackexchange.com/questions/31510/why-are-the-palms-of-hand-salty</a></p>
<p>I am agreeing heads on that the data provided has not been recorded in any scientific literature (I am not able to find any). However it is easily verifiable by everyone and if false could be pointed out after which the question can be closed as false data.</p>
<p>However, the people who voted to close the question gave a very interesting reason:</p>
<blockquote>
<p>put on hold as primarily opinion-based by GriffinEvo, poka.nandor, WYSIWYG, March Ho, Luigi 11 hours ago</p>
<p>Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise.
If this question can be reworded to fit the rules in the help center, please edit your question.</p>
</blockquote>
<p>I was thinking that good question which do not have an answer as of now <em>are not closed</em>. This is what the moderator said in one of his comments here:</p>
<p><a href="https://biology.meta.stackexchange.com/questions/2892/suggest-expanding-biologys-scope">Suggest expanding Biology&#39;s scope</a></p>
<blockquote>
<p>@OneFace The fact that the answer isn't known yet is not a reason to close a question. –  Mad Scientist♦</p>
</blockquote>
<p>Infact there were 4 people who upvoted this comment showing they agree with this idea. But my question got closed. Please explain how some questions with no answer as of yet are kept open while others are closed.</p>
<p>I was of the idea that opinion based close reason are for <em>questions</em> that are opinion based!</p>
 10456: <p>In addition to the reason provided by poka.nandor, my personal take on the matter is that it seems to be the case that the issue of salty palms itself does not appear to be universally applicable. If only a small fraction of people have salty palms, and the problem of salty palms does not appear to be a medically significant problem, there is unlikely to be any significant research done to quantify the issue, unlike the questions given as an example <a href="https://biology.meta.stackexchange.com/questions/763/what-is-to-be-done-with-questions-that-have-no-answers-yet">here in this thread</a>, which seem to be areas of active research within well-defined fields. </p>

<p>Therefore, it is unlikely to be the case that any decent citable research is likely to be done on this topic in the near future, and therefore any answer is likely to be opinion based in the forseeable future. </p>
 14735: <p>In my interpretation this reason means that the question cannot be answered by scientifically proven fact(s) (basically this is written in the explanation), a thing that this site want to avoid. The question itself may not be opinion based, but the answers it generates would be, and that is the real reason for closure. The question itself is interesting on its own, but I don't remember feeling difference in the saltiness of my own sweat from different parts of my body, although I haven't licked myself too much... As AliceD pointed out in the comments it's quite a gray area.</p>

<p>How it is determined if the question would generate opinion based question? I think when the question is clear enough to get the point (so we know what the OP wants to find out), but it is either based on anecdotal (personal) evidence, or there is no literature at all, is when this type of reason is chosen. There are people here with more routine, may can provide a better answer.</p>
