In: Chemistry
100 mL of a river water sample took 9.30 mL of 0.01005 M Ag+ to titrate. Calculate the concentration of Cl- in ppm (μg/mL or mg/L) for the river water.
no of moles of Ag+ = molarity * volume in L
= 0.01005*0.0093 = 9.3465*10-5 moles
Ag+ + Cl- -------> AgCl
since Ag+ and Cl- react in a 1:1 ratio
no of moles of Cl- = no of moles of Ag+
no of moles of Cl- = 9.3465*10-5 moles
mass of Cl- = no of moles * gram atomic mass
=9.3465*10-5 * 35.5 = 3.31*10-3 g
= 3.31mg
=3.31mg/0.1093L [ total volume = 100+9.3 = 109.3ml =0.1093L]
= 30.28mg/L