[akxt]

Please check my work and tell me what i am doing wrong,

What is the hydroxide ion concentration in a solution formed by combining 200mL of .15M HCl and 300mL of .091M NaOH @25*C?

(.15)(.2) = .03mol HCl
.03mol / .5L = .06M

(1.0*10^-14) = .06M [OH-]

[OH]- = 1.67 x 10^-13 M

Did I do this right? The answer key says the answer should be 1.9 x 10^-12M.
Thanks!!

[Astrokel]

What is the moles of HCl?
What is the mole of NaOH?
After neutralization, how many moles of NaOH left?