Aforce of attraction/repulsion due to the spin of electrons what is this force?

27.64 liters

Explanation:

From the balanced equation, 2 moles of K2Cr2O7 requires 3 moles of CH3OH.

Mole of CH3OH = 1.9/32.04 = 0.0593 mole

Mole of K2Cr2O7 that will require 0.0593 mole of CH3OH:

                   2 x 0.0593/3 = 0.0395 mole

mole = molarity x volume

Volume of K2Cr2O7 needed = 0.0395/0.00143

                             = 27.64 Liter

Hence, 27.64 liters of 0.00143 M K2Cr2O7 will be required to titrate 1.90 g of CH3OH dissolved in 50.0 mL of solution