## Chemistry (7th Edition)

$[H_3O^+] = [OH^-] = 4.123\times 10^{- 10}M$ The solution is neutral
- Pure water solution : $[H_3O^+] = [OH^-]$ - Create an unknown called 'x', that has the value of $[H_3O^+] and [OH^-]$ - Write the $K_w$ expression, and calculate the x value: $[H_3O^+] * [OH^-] = K_w = 1.7\times 10^{- 19}$ $x * x = 1.7\times 10^{- 19}$ $x^2 = 1.7\times 10^{- 19}$ $x = \sqrt { 1.7\times 10^{- 19}}$ $x = 4.123\times 10^{- 10}$ Therefore: $[H_3O^+] and [OH^-] = 4.123\times 10^{- 10}M$ Since $[H_3O^+] = [OH^-]$, the solution is neutral.