Question #f2d31
1 Answer
Explanation:
Your starting point here will be to pick a sample of this potassium chloride solution. To make the calculations easier, let's pick a sample that contains exactly
As you know, the molality of the solution tells you the number of moles of solute present in exactly
In your case, a
Use the molar mass of potassium chloride to convert the number of moles to grams
#0.273 color(red)(cancel(color(black)("moles KCl"))) * "74.55 g"/(1color(red)(cancel(color(black)("mole KCl")))) = "20.35 g"#
So, this sample contains
#10^3color(white)(.)"g" + "20.35 g" = "1020.35 g"#
Next, use the density of the solution to find its volume.
#1020.35 color(red)(cancel(color(black)("g solution"))) * "1 L solution"/(1.011 * 10^3color(red)(cancel(color(black)("g")))) = "1.00925 L solution"#
Now, in order to find the molarity of the solution, you need to figure out how many moles of solute are present in exactly
Use the fact that
#1 color(red)(cancel(color(black)("L solution"))) * "0.273 moles KCl"/(1.00925color(red)(cancel(color(black)("L solution")))) = "0.270 moles KCl"#
You can thus say that this solution has a molarity of
#color(darkgreen)(ul(color(black)("molarity = 0.270 mol L"^(-1))))#
The answer is rounded to three sig figs, the number of sifg figs you have for your data.