How many mol of NaOH are present in 66mL of 0.5M solution?
0.03mol (With sig figs)
Given that we have a 0.5M solution, that can be rewritten as 0.5mol/1 L.
Convert the 66mL to L.
Then, multiply by the molarity to find the moles of solution.
With sig figs, 0.03.