# Problem: Using modern analytical techniques, it is possible to detect sodium ions in concentrations as low as 70 pg/mL .  (a) What is this detection limit expressed in molarity of Na+?  Express your answer using two significant figures.

###### Problem Details

Using modern analytical techniques, it is possible to detect sodium ions in concentrations as low as 70 pg/mL .  (a) What is this detection limit expressed in molarity of Na+?  Express your answer using two significant figures.