A student prepares 200mL of 0.01 M solution of calcium phosphate. what is the concentration of calcium in parts per million?

1 Answer
Apr 17, 2018

#25.80ppm#

Explanation:

200mL of 0.01M solution of calcium phosphate #(Ca_3(PO_4)_2)#
Remember that parts per million can also equal to mg/L

Using the equation # concentration= "moles" /"volume"#

#0.01="moles"/0.2#

#"moles"=0.002#

Using the equation #"moles"="mass"/"molar mass"#

#0.002= "mass"/ (40.08times3+30.97times2+16times4times2)times(40.08times3)#

#"mass of calcium" = 0.0052g = 5.16mg#

Therefore, there are #5.16mg# of calcium in #200ml# of 0.01M of calcium phosphate.

Hence, #25.797mg# of calcium in #1L# of 0.01M of calcium phosphate. Therefore, concentration of calcium in parts per million is #25.80"ppm"#