A sample of water has hardness expressed as 160 ppm Ca2+(aq). The sample is passed through an ion exchange column and the Ca2+(aq) ions are replaced by Na+(aq) ions. What is the [Na+] in ppm of the water after it has been treated? (1 ppm = 1 g solute/106 g solution)
◦ 46.0 ppm
◦ 92 ppm
◦ 184 ppm
◦ 320 ppm
◦ 80.0 ppm