Answer:
0.287 M
Step-by-step explanation:
Multiply the concentration of each solution by the volume of each (in liters) to get the moles of NaOH in that solution.
0.15 M • 5.4000 L = 0.81 mol NaOH
4.0 M • 0.2012 L = 0.80 mol NaOH
Add the mol of NaOH together to get the total --> 0.81 + 0.80 = 1.61 mol NaOH
Divide by the total volume of solution (5400.0 mL + 201.2 mL = 5,601.2 mL = 5.6012 L)
1.61 mol / 5.6012 L = 0.287 M NaOH