What is the percent by mass of sodium phosphate in a 0.142 M Na₃PO₄(aq) solution that has a density of 1.015 g/mL A) 2.09 % B) 2.29 % C) 2.49 % D) 2.69 % E) None of the above

Question

Quizplus · Accepted Answer

To find the percent by mass of sodium phosphate, we need to first calculate the mass of Na3PO4 present in 1 liter of the solution.

We know that 1 mole of Na3PO4 weighs 163.94 g and that the concentration of the solution is 0.142 M. This means that in 1 liter of the solution, there are:

0.142 moles/L × 163.94 g/mole = 23.595 g/L of Na3PO4

Next, we use the density of the solution to convert this to the mass percent:

1.015 g/mL × 1000 mL/L = 1015 g/L

So the percent by mass of Na3PO4 in the solution is:

23.595 g/L ÷ 1015 g/L × 100% = 2.29%

Therefore, the best answer choice is B.

What Is the Percent by Mass of Sodium Phosphate in a 0.142