<p>An aqueous solution of sodium fluoride is 18.0% by mass and has a density of 1.18 g/ ml. </p>
<p>a. How many grams of sodium fluoride are contained in 150. mL of solution?<br>
31.9 g </p>
<p>b. What is the molarity of the solution? 5.07 M</p>
<p>c. How many milliliters of solution contain 136 grams of water? I'm not sure how to do this. Any suggestions? Thanks : )</p>
<p>a. 150 mL * (1.18 g/mL) = 177 g
177 g * (0.180) = 31.9 g NaF</p>
<p>b. 31.9 g NaF * (mol NaF/41.99 g NaF) = 0.760 mol NaF
0.760 mol NaF/0.150 L = 5.07 M NaF soln</p>
<p>c. There is 82% water and 18% NaF by mass. So, we can say that 136 = x - 0.18x, or that 136 will result after we take the total number of grams of solution and subtract the portion of it that is NaF.</p>
<p>Solving that equation (which is a common SAT I math problem, lol) yields x = 166 g.</p>
<p>166 g * (mL/1.18 g) = 141 mL. Do you know if this is the correct answer?</p>
<p>Hope this helps.</p>
<p>no, we didnt get them.... i actually got a and b-- sorry that you figured them out! i just didnt know how to do c</p>