## Chemistry (4th Edition)

It's necessary $2.184 \times 10^{-3}g$ of NaOH.
1. Find the $[OH^-]$ needed in this solution: pH + pOH = 14 10 + pOH = 14 pOH = 4 $[OH^-] = 10^{- pOH}$ $[OH^-] = 10^{- 4}M$ 2. Since NaOH is a strong base: $[NaOH] = [OH^-] = 10^{-4}M$ Therefore, we need this concentration of NaOH. 3. Find the number of moles needed: $n(moles) = Concentration(M) * Volume(L)$ - 546 ml = 0.546L (ml to L, divide by 1000) $n(moles) = 10^{-4} * 0.546$ $n(moles) = 5.46 \times 10^{-5}$ 4. Using the molar mass, convert this number to grams. - Molar mass ($NaOH$): 23* 1 + 16* 1 + 1* 1 = 40g/mol $mass(g) = mm(g/mol) * n(mol)$ $mass(g) = 40 *5.46 \times 10^{-5} = 2.184 \times 10^{-3}$