12A 1 Making up a buffer solution

What mass of sodium ethanoate must be added to 250 mL of 0.1 mol L-1 CH3COOH to make a buffer solution with a pH of 6.0? Ka(CH3COOH) = 1.74 x 10-5, M(CH3COONa) = 86 g mol-1.

Put these steps in the calculation in the correct order.