Should the Town Buy NaCl or CaCl2 for De-icing?”

  • Thread starter jdhutto
  • Start date
In summary, the town can obtain NaCl for $0.36/kg, but CaCl2 will be cost effective if bought for $1.05/kg.
  • #1
jdhutto
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Homework Statement




"De-icing salt" is used to melt snow and ice on streets. the highway department of a small town is decideing whether to by NaCl or CaCl2 for the job. The town can obtain NaCl for $0.36/kg. What is the maximum the town should pay for CaCl2 to be cost effective? in kg



Homework Equations





The Attempt at a Solution




I am sure this is very simple but I am not sure what to do with it...
 
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  • #2
Do you know about moles and molar mass of compounds?
Do you know how to work out how much NaCl there is in a kg?

You have posted 3 questions which are basically the same thing - they all need this step.
 
  • #3
I am really not sure...i am pretty new to chemistry and not very good at it, can i get some help
 
  • #4
Can you work out how many moles are in 1 kg of NaCl and CaCl2? What part are you confused on?
 
  • #5
i worked out .05844 mol in 1 kg for NaCL
and .11098 mol in 1 kg of CaCl2

is this correct
 
  • #6
No, molar mass of NaCl is 58.4g, CaCl2 is 111g
but for every mole of CaCl2 you get twice as much Cl as you do from NaCl

So 1kg of NaCl gets you 17.12moles of Na and Cl, 1kg of CaCl2 is 9.0 moles of Ca and 18.0moles of Cl

It isn't clear from the question if you supposed to take into account the de-icing effect of the Cl ion so the answer is either.
That you should pay 9/17.2 = 0.52 times as much for CaCl2
or if you are only concerned about Cl then you should pay 18/17.2 = 1.05 times as much for CaCl2


(Actually it's a very stupid example because CaCl2 is so hydroscopic it will almost certainly not be 111g/mole - but since this is an intro chemistry question you can ignore this)
 
Last edited:

Related to Should the Town Buy NaCl or CaCl2 for De-icing?”

1. What is the difference between NaCl and CaCl2 for de-icing?

NaCl, or sodium chloride, is commonly known as table salt. CaCl2, or calcium chloride, is a salt that is typically used for industrial purposes. The main difference between these two salts is their chemical composition, with CaCl2 being a more potent de-icer due to its ability to absorb more water and generate more heat.

2. Which salt is more cost-effective for de-icing?

In general, NaCl is more cost-effective than CaCl2 for de-icing purposes. This is because NaCl is a more abundant and inexpensive resource compared to CaCl2. However, the effectiveness of each salt may vary depending on the specific conditions and temperature of the area being de-iced.

3. Is one salt more environmentally friendly than the other?

Both NaCl and CaCl2 can have negative impacts on the environment if used in excessive amounts. However, NaCl is considered to be more environmentally friendly because it is a natural resource and does not have as strong of a negative impact on plants and wildlife compared to CaCl2.

4. Which salt is safer for roads and vehicles?

Both NaCl and CaCl2 can corrode metals and damage vehicles when used in large quantities. However, CaCl2 is known to be more corrosive than NaCl, so in terms of safety for roads and vehicles, NaCl may be a better option.

5. Which salt is more effective for de-icing in extreme temperatures?

In extreme temperatures, CaCl2 is typically more effective for de-icing compared to NaCl. This is because CaCl2 can generate heat and melt ice at lower temperatures than NaCl. However, NaCl can still be effective in most winter conditions and is a more cost-effective option.

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