basic chemistry questions for tegger

On 10/29/2011 05:38 PM, Bret wrote:
> On Fri, 28 Oct 2011 20:21:56 -0700, jim beam wrote:
>
>> On 10/28/2011 07:27 PM, Bret wrote:
>>> On Fri, 28 Oct 2011 18:50:10 -0700, jim beam wrote:
>>>
>>>> On 10/26/2011 04:18 PM, jim beam wrote:
>>>>> 1. if i have a 5l radiator/coolant system full of hard water, and that
>>>>> hard water has a carbonate content of 200mg/l, how much dry carbonate
>>>>> would i be left with if i boil that water completely away?
>>>>>
>>>>> 2. if i distribute that carbonate over a surface area of 2m^2, how thick
>>>>> will that layer be? [use a density of 2.0g/cm^3.]
>>>>>
>>>>> 3. how many liters of water do i need to boil dry to deposit this
>>>>> surface up to a thickness of 0.3mm?
>>>>>
>>>>>
>>>>
>>>> since tegger's sulking, i guess i need to do this myself.
>>>>
>>>> 1: with solute content of 200mg/l [which is very hard water indeed btw],
>>>> 5 liters will give 1.000g of carbonate.
>>>>
>>>> 2: 1.000g over 2m^2 = 0.500g/m^2, or 0.00005g/cm^2. at a density of
>>>> 2.0g/cm^3 that gives a thickness of 0.0001cm, or 1 micron.
>>>>
>>>> 3: at the rate of 0.0001cm/liter, you'd have to boil 3,000l [~793
>>>> gallons] of water to accumulate 0.3mm depth of carbonate scale.
>>>>
>>>>
>>>> it's a legitimate question to wonder where the hard "rock" that
>>>> accumulates in radiators comes from. but the above hopefully
>>>> illustrates that only a small proportion of it can come from using hard
>>>> tap-water. instead, the majority comes from corrosion product within
>>>> the engine and cooling system itself, and from decay of the antifreeze.
>>>>
>>>> antifreeze contains salts and corrosion agents that protect by rapidly
>>>> increasing the initial corrosion rate in the system to build up a
>>>> passive layer. that passive layer exists in equilibrium with the
>>>> coolant chemistry to prevent further corrosion for as long as the
>>>> solution remains within its intended range. if diluted out of that
>>>> range, or if other chemicals are introduced, equilibrium is upset,
>>>> passivation can cease and non-passive corrosion starts again.
>>>>
>>>> as to why we see a lot of it accumulate in the radiator, the solubility
>>>> of a lot of these compounds increases with elevated temperatures, and
>>>> decreases with decreasing temperature. just like the solubility of salt
>>>> or sugar in water increases with temperature. thus we see dissolved
>>>> material transported form the heat source, the engine, precipitating
>>>> where it's cooler, the radiator.
>>>
>>> You have made an error, how does it feel
>>
>> i dunno - how does it feel to be hiding behind mommy's skirts by not
>> substantiating your allegation?
>
> I thought it would be more constructive for you to find your own error.

based on some of your past performances, you probably think "legitimate"
is spelled wrong.


--
nomina rutrum rutrum

Let me try to guess what his error is.
He states that the solubility of CaCO3 increases with temperature but
that is not always true.
It's solubility is determined by the amount of CO2 present, the higher
the CO2 content the more soluble CaCO3 is but like most gases the
solubility of CO2 in water decreases with temperature.
Therefore we have a trade off at a certain temperature where calcium
carbonate becomes less soluble with temp increase.
That's why you're more likely to see scale in hot water pipes.
http://en.wikipedia.org/wiki/Calcium...g_CO2_pressure
Engineman
>
>
>
>
> >>>> as to why we see a lot of it accumulate in the radiator, the solubility
> >>>> of a lot of these compounds increases with elevated temperatures, and
> >>>> decreases with decreasing temperature. *just like the solubility of salt
> >>>> or sugar in water increases with temperature. *thus we see dissolved
> >>>> material transported form the heat source, the engine, precipitating
> >>>> where it's cooler, the radiator.
>
> >>> You have made an error, how does it feel
>
> >> i dunno - how does it feel to be hiding behind mommy's skirts by not
> >> substantiating your allegation?
>
> > I thought it would be more constructive for you to find your own error.
>
> based on some of your past performances, you probably think "legitimate"
> is spelled wrong.
>
> --
> nomina rutrum rutrum

On 10/29/2011 06:56 PM, wrote:
>>
>>>>>> as to why we see a lot of it accumulate in the radiator, the solubility
>>>>>> of a lot of these compounds increases with elevated temperatures, and
>>>>>> decreases with decreasing temperature. �just like the solubility of salt
>>>>>> or sugar in water increases with temperature. �thus we see dissolved
>>>>>> material transported form the heat source, the engine, precipitating
>>>>>> where it's cooler, the radiator.
>>
>>>>> You have made an error, how does it feel
>>
>>>> i dunno - how does it feel to be hiding behind mommy's skirts by not
>>>> substantiating your allegation?
>>
>>> I thought it would be more constructive for you to find your own error.
>>
>> based on some of your past performances, you probably think "legitimate"
>> is spelled wrong.
>>
>> --
>> nomina rutrum rutrum
>
> Let me try to guess what his error is.
> He states that the solubility of CaCO3 increases with temperature but
> that is not always true.
> It's solubility is determined by the amount of CO2 present, the higher
> the CO2 content the more soluble CaCO3 is but like most gases the
> solubility of CO2 in water decreases with temperature.
> Therefore we have a trade off at a certain temperature where calcium
> carbonate becomes less soluble with temp increase.
> That's why you're more likely to see scale in hot water pipes.
> http://en.wikipedia.org/wiki/Calcium...g_CO2_pressure
> Engineman

but it's not an open system - you can't just buffer in and out from
atmospheric.


--
nomina rutrum rutrum

On Sat, 29 Oct 2011 18:56:36 -0700 (PDT), wrote:

> Let me try to guess what his error is.
> He states that the solubility of CaCO3 increases with temperature but
> that is not always true.
> It's solubility is determined by the amount of CO2 present, the higher
> the CO2 content the more soluble CaCO3 is but like most gases the
> solubility of CO2 in water decreases with temperature.
> Therefore we have a trade off at a certain temperature where calcium
> carbonate becomes less soluble with temp increase.
> That's why you're more likely to see scale in hot water pipes.
> http://en.wikipedia.org/wiki/Calcium...g_CO2_pressure
> Engineman
>>
>>
>>
>>
>>>>>> as to why we see a lot of it accumulate in the radiator, the solubility
>>>>>> of a lot of these compounds increases with elevated temperatures, and
>>>>>> decreases with decreasing temperature. *just like the solubility of salt
>>>>>> or sugar in water increases with temperature. *thus we see dissolved
>>>>>> material transported form the heat source, the engine, precipitating
>>>>>> where it's cooler, the radiator.

2 errors then.

>>>>> You have made an error, how does it feel
>>
>>>> i dunno - how does it feel to be hiding behind mommy's skirts by not
>>>> substantiating your allegation?
>>
>>> I thought it would be more constructive for you to find your own error.
>>
>> based on some of your past performances, you probably think "legitimate"
>> is spelled wrong.
>>
>> --
>> nomina rutrum rutrum