when titrating 50 mL of .10M H2SO45 with .10 M NaOH, how many mL of NaOH will you have added to reach first equivalence point?

Answer 1

NaOH + H2SO4 ==> NaHSO4 + H2O
You have 0.1M x 50 mL = 5 millimols H2SO4. Therefore, to reach the first equivalence point you must titrate 5 millimols (another 5 millimols will be needed to titrate the second H).
So you will need 50 mL of 0.1M NaOH to titrate that first H and another 50 to titrate the second H.