Calculate the [H3O+] of an aqueous solution that is 1.94 × 10−7 M in OH−. Enter your answer in scientific notation.

Answer 1

From the equilibrium of water auto-ionization: [hydronium][hydroxide] = K_w (=10^-14 at room temp)

K_w/{hydroxide] = {hydronium}

Consider hiring a tutor. Take care.

Answer 2

You should use the relation that [H3O+] x [OH-] = 10^-14

Substitute the given OH- concentration into the above equation and solve for [H3O+].

I got 5.15 x 10^-8