Question

Calculate the mass of sodium phosphate required to make 500. ml of 0.350 M solution?
a. After the solution is produced, what is the molarity of the sodium ions in this solution?

Answer 1

Explanation:

molarity=n/vol

0.35=n/0.5L

n=0.175mol

n=mass/molar mass

molar mass=163.94g/mol

0.175=mass/163.94

mass of Na3PO4 is 28.6895g

molarity Na ions

Na3PO4====>3Na+ + PO4^-3

sodium phosphate disociayes as follows in water

now

28.6895 mol of na3po4 is present in 0.5Lsolution

so in 1L of solution ther will be

28.6895/0.5L=57.379mol

now by diamensional analysis

57.379mol na3po4/1L × 3 mol Na+ ions/1na3po4

=172.137M