My answer to a) is wrong. I have two probable answers 1)75 ml of K

_{2}Cr

_{2}O

_{7}.

It is computed as under:

0.3 M = 300 mmol :rarrow:50 ml of 300mmol = 15mmol

So volume of Potassium Dichromate × 0.2 M = 15mmol

volume of K

_{2}Cr

_{2}O

_{7}= 75 ml

2) Using this formula v.f.

_{1} × M

_{1} × volume

_{1}= v.f.

_{2}× M

_{2} × volume

_{2}Plugging in the values available with us into this formula, we have 6×0.2M× V

_{1}=2×0.3M × 50 ml

= 25 ml of Potassium Dichromate

Which of the above answer is correct?