Ocean water is found to contain 7.2 g of NaCl, what is the molarity ?

In summary, the conversation is discussing the process of calculating the molarity of a solution, specifically with regards to NaCl. The steps involve converting the volume of ocean water to liters, converting the mass of NaCl to moles, and then dividing the moles of NaCl by the total volume in liters to determine the molarity. The purpose of the inquiry is not disclosed, but it is clarified that the calculation is only for the molarity of NaCl, not any other salts present in the solution. Additionally, the conversation leads to the mention of resources such as chemical calculators and titration methods.
  • #1
land_of_ice
137
0
A 205 mL sample of ocean water is found to contain 7.2 g of NaCl, what is the molarity of the solution?
(The problem also says, with respect to NaCl?)
Ok, now, what do they mean with respect to NaCl?

What is it usually in respect to?

Anyways is this the correct way to do this?

Recognize that NaCl is the solute, and the ocean water is the solution, then, you convert the 205 mL of ocean water to Liters and also you have to convert the 7.2 g of NaCl to mL, then L to add it with the ocean water because molarity is moles of solute divided by Liters of total solution isn't it? And then you just divide the solute converted into moles into that to determine the molarity?
 
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  • #2
Please disclose the purpose of your inquiry...is this homework or a personal endeavor?
 
  • #3
In regards to your second paragraph, yes.

Molar Mass of 7.2 g NaCl / Volume of water in litres. No need to convert NaCl to ml, as molarity is the moles of solute [any solute] within a given volume [usually 1 litre].
 
  • #4
Lazy said:
Molar Mass of 7.2 g NaCl.

Huh? I guess you meant something else.

--
methods
 
  • #5
land_of_ice said:
(The problem also says, with respect to NaCl?)
Ok, now, what do they mean with respect to NaCl?

What is it usually in respect to?

There can be (and in sea water are) other salts dissolved, you are asked to calculate only molarity of the NaCl.

you have to convert the 7.2 g of NaCl to mL, then L to add it with the ocean water because molarity is moles of solute divided by Liters of total solution isn't it? And then you just divide the solute converted into moles into that to determine the molarity?

205 mL is a total volume, you don't need any tricks to calculate it. Just convert 7.2g to moles of NaCl and divide as you wanted to.

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1. What is molarity and why is it important in ocean water analysis?

Molarity is a unit of concentration that represents the number of moles of a substance per liter of solution. In the case of ocean water analysis, it is important because it helps us understand the amount of dissolved salts in the water, which can have significant impacts on marine life and ocean ecosystems.

2. How is the molarity of ocean water determined?

The molarity of ocean water is determined by measuring the amount of a particular substance (in this case, NaCl) in a given volume of water, and then using the molar mass of that substance to calculate the number of moles. The molarity is then calculated by dividing the number of moles by the volume of the solution in liters.

3. What is the significance of finding 7.2 g of NaCl in ocean water?

The significance of finding 7.2 g of NaCl in ocean water is that it indicates a relatively high concentration of dissolved salts. This can have implications for the salinity, density, and overall chemical balance of the water, which can affect marine life and ocean currents.

4. How does the molarity of ocean water vary around the world?

The molarity of ocean water can vary significantly around the world due to a variety of factors, including proximity to land (which can introduce additional dissolved substances), ocean currents, and evaporation rates. Generally, the molarity of ocean water is highest in areas closer to the equator and decreases towards the poles.

5. What other substances are typically found in ocean water, and how do their concentrations compare to that of NaCl?

In addition to NaCl, ocean water also contains a variety of other dissolved substances, including magnesium, calcium, and potassium ions. The concentrations of these substances vary, but they are generally present in much lower amounts compared to NaCl. For example, the average concentration of magnesium in ocean water is about 1,300 parts per million, while the concentration of NaCl is about 35,000 parts per million.

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