A 250.ml volmetric flask contains 7.36g of potassium dichromate and dissolved water up to the calibration mark.
a) Determine the concentration of the solution.
b) Write a dissociation equation for the solution and inficae the concentraton of the cation and anion
2007-05-25 07:36:18 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
a) Conc. in which units ??????????
b) K2Cr2O7 -> 2K+ (Cation) + Cr2O7(2-) (Anion)
2007-05-25 07:54:58 · answer #1 · answered by ag_iitkgp 7 · 0⤊ 0⤋
easy.
so u know the volume of the solution (250ml or better 0.25L). what u need is the amount of substance in moles.
u can get if, if u divide the amount of substance (7.36g) by the molecular weight of the substance (in g/mol).
the molecular weight u can calculate by adding up the atomic weights of the corresponding atoms, taken from the periodic table.
2007-05-25 07:52:22 · answer #2 · answered by chem_freak 5 · 0⤊ 0⤋
Proper ,answer will be 3.33 percent (just do your basic maths.)...one quarter of a liter is 250 ml...one quarter of 7.36 is 3.33...and that is the percentge of the solution at hand....
2007-05-25 08:21:18 · answer #3 · answered by Sehr_Klug 50 6 · 0⤊ 0⤋
concentration= no. of moles/volume, now no. of moles = mass/molar mass =7.36/315=0.0234, conc. = 0.0234/250*1000 =0.0934 mol/L
2007-05-25 09:23:17 · answer #4 · answered by sillu s 2 · 0⤊ 0⤋