"Cowardice asks the question...is it safe? Expediency asks the question...is it politic? Vanity asks the question...is it popular? But conscience asks the question...is it right? And there comes a time when one must take a position that is neither safe, nor politic, nor popular but one must take it because it is right." ~Dr. Martin Luther King

Wednesday 13 August 2014

Guest post

KA-NON has left a new comment on your post "Pedantic...Maybe. Precise...Hardly":


@12:17 - My understanding is that, upon scrutiny, Wikipedia is roughly as accurate as the best collections of encylopedias have ever been (i.e. Britannica). They've studied this, apparently.
see the link below

http://news.bbc.co.uk/2/hi/technology/4530930.stm

Having said that, the real point to be made is that the specific link that Cllr. Pirri presents does not effectively challenge Evelyn's point. It merely changes the temperature of it.

Below is a Wikipedia excerpt, on the solubility of salt in water. FYI NaCl is the chemical formula for Salt.

"When dissolved in water, the sodium chloride framework disintegrates as the Na+ and Cl− ions become surrounded by the polar water molecules. These solutions consist of metal aquo complex with the formula [Na(H2O)8]+, with the Na-O distance of 250 pm. The chloride ions are also strongly solvated, each being surrounded by an average of 6 molecules of water.[4] Solutions of sodium chloride have very different properties from pure water. The freezing point is −21.12 °C (−6.02 °F) for 23.31 wt% of salt, and the boiling point of saturated salt solution is near 108.7 °C (227.7 °F).[5] From cold solutions, salt crystallises as the dihydrate NaCl·2H2O."

The link for the above
this excerpt is below.

http://en.wikipedia.org/wiki/Sodium_chloride

So, at a temperature ABOVE -21.12 celcius, the salt melts the snow and is then dissolved in the resulting water, which would have otherwise been frozen at 0 degrees. That is indeed the whole point - melt the snow and ice so that tires can grip the road underneath. The snow/salt water solution then flows where gravity takes it, meaning, the salt does not take up residence in the snow.

At temperatures BELOW -21.12 degrees celcius, I believe that the salt would remain among the snow and ice. So on those days, the snow that is picked up would have salt in its midst.

This link

http://www.worldweatheronline.com/Newmarket-weather-averages/Ontario/CA.aspx

provides the average daily temperatures throughout the year for Newmarket (closest to Aurora on the site). The coldest months, on average, are January and February, with an average daily temperature of -9 degrees celcius. Now of course, we all know that there are some cold days that are below -21 degrees - but not many. Less than a handful each year, I would bet. Remember, we are NOT talking wind-chill - just temp.

So, notwithstanding Cllr. Pirri's freezing point depression point, for all practical purposes, it seems that Evelyn's theory is correct. That is, the salt melts the snow and ice (yay - fewer traffic accidents!) and the resultant liquid solution goes where Newton knew it would.

One more thing. In places that DO have sustained temperatures below -21.12 celcius, they don't use salt on the roads. They use dirt as a grit to provide traction ON TOP OF the ice. Now you know why.


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Posted by KA-NON to Our Town and Its Business at 13 August 2014 13:04

12 comments:

Anonymous said...

My only small quibble with KA-NON is that he tends to hit an ace after the match has been decided.

Anonymous said...

Hindsight is 20/20.

KA-NON said...

Sorry, @19:45, however Evelyn needed to post Cllr. Pirri's email before anyone could respond to it, including me. Next time, I will try to look into the future in order to respond to a post that is not up yet! ;-)

Like the tennis metaphor, though!

Regarding Cllr. Pirri's email which was the basis of Evelyn's post, I think what made me want to whack it into next week (hey, a future reference again!), is the tone that I inferred from it. Arrogant and condescending is how it came off to me. as in, "there, there, my little white haired granny, here is a link which refutes your position of last night, however you probably won't understand it anyway."

I know he didn't SAY that, and he may well respond to this saying he did not INTEND it. And he probably didn't. That's how it read to me, though.

Anonymous said...

Perhaps a correction and a bit more research is in order.

I haven't been following this issue closely but... yes, "The freezing point is −21.12 °C (−6.02 °F) for 23.31 wt% of salt" - this is for what appears to be a saturated solution under laboratory conditions. Saturated solution means the water has desolved as much salt as it possibly can under normal conditions.

Spreading road salt comes no where near a saturated solution and so salt helps to about perhaps -9 degrees C (from other sources & should be verified see below), below that point is the reason they switch to sand like mixes. Perhaps it's best to consult the Town of Aurora's Infrastructure & Environmental Services Dept. (what used to called the Town Works Dept.) and ask them at what temperatures they use salt and switch over. The facts at Wikipedia may be true but for the wrong application. I don't know how the temperature figures into the rest of the issue.

Anonymous said...

It is a shame that Scott from the Auroran is not running for election. ButI would not want to lose him from writing & drawing for the paper.
On a snarky note: One candidate for Council is slamming another for not living the town long enuff. He seems to have forgotten the attempted candidate from last term who did not even have a residence here.

Anonymous said...

7:36
Thank you for the clarification.
I guess my point was that when you do step up it is usually worth reading your comments.
Just too long between matches ?

Anonymous said...

Great post. Pirri it's your move...

Take the high road or lose my vote.

Anonymous said...

12:23
The voting on the salt-non-removal was instructive. There is some shape-shifting occurring.

Anonymous said...

"I know he didn't SAY that, and he may well respond to this saying he did not INTEND it. And he probably didn't. That's how it read to me, though."

You read far too much into it, KA-NON. Try reading it again, without your biases.

Anonymous said...

12:23- He lost my vote a long time ago.

Anonymous said...

14:20
Don't worry - I don't think he thought he had your vote.

Anonymous said...

9:09
I think what has happened here is that during the last election it seemed imperative to bring in new councillors & people who volunteered to give it a shot received a coronation of sorts. Now they are going to actually have to earn those votes that flowed so freely.