75.0g NaOH x [1 mole / 40.0g NaOH] = 1.875 moles of NaOH
Now you want to do a mole to mole ratio, where you compare the amount of moles between NaOH and H2O using their coefficients. (the number before the compound)
1.875 moles NaOH x [ 2 moles H2O / 2 moles NaOH] = 1.875 moles of H2O
Finally you can do a mole to mass conversion using the moles and the molar mass of H2O
1.875 moles H2O x [ 18g H2O / 1 mole H2O] = 33.75g of H2O or w/ sig figs = 34.0g H2O.
To make it easier on yourself you can combine all of these into a mass to mole to mole to mass conversion, and it would look like this:
75.0g NaOH x [1 mole / 40.0g NaOH] x [ 2 moles H2O / 2 moles NaOH] x [ 18g H2O / 1 mole H2O] = 34.0g H2O
Hope I helped! stoichiometry can be a handful but the more you analyze it the more you understand it, and sorry for not doing the percent yield but i think the people above me explained it well enough.