I have deleted my answer to your earlier post.That answer I gave was partially right but not 100% right. Here is how the answer comes up to be 0.0376 BUT I'm not ready to buy into the solution. This is just to show you how the author came up with that answer.
1.22 g/mL x 10.0 mL = 12.2 grams is the mass of the solution. Then assume that volume of 10.0 mL is all water then with density of 1.0 g/mL for H2O that makes the water part have a mass of 10.0 grams.(Said another way 10 g H2O + 2.2 g NaCl = 12.2 g solution.) The total is 12.2 so the mass NaCl is 2.2g.
Then mols is 2.2/58.5 = 0.0376.
But I don't think that manipulation is legal. It is true that if you take 2.2 g NaCl and add it to 10.0 mL H2O that the mass of the solution will be 12.2 grams; HOWEVER, the volume of the solution will NOT be 10.0 mL but more like 11 or so and that density is not 1.22. I don't think you can work this problem without knowing the percent NaCl because while the solution has a mass of 12.2g you don't know how much is NaCl and how much is H2O with a percent. I don't think I've missed anything here but if I have I hope someone will let me know.
A sodium chloride solution has a density of 1.22 g/mL. How many moles of NaCl are dissolved in 10.0 mL of the solution? The density of water is 1.00 g/mL.
My solution:
? mol NaCl = 10 mL*1.22 g/1mL*1mL/58.5g
The correct answer is 3.76E-2 mol.
Please help!
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