posted by Jessica .
0.125g of sodium dichromate is to be reacted wtih 0.025M potassium iodide. How many mLs of the potassium iodide solution will be needed.
1. balance equation is;
Na2Cr2O7 + 2KI --> 2NaI + K2Cr2O7
mass of Na2Cr2O7 = 0.125g
mole of Na2Cr2O7 = m/Mr = 0.125g/Mr =___mole
Na2Cr2O7 : KI
1 : 2
2.calculate the mole of KI using the mole ratio above and mole of Na2Cr2O7.
volume of KI = n/M where n is the mole you calculate in 2 for KI and M is the molarity of KI.
the molarity is in mol/L so the volume you will get is in liters.
hope that helps..