Question

What volume (mL) of 0.0855 M phosphoric acid can be neutralized with 119 mL of 0.315 M sodium hydroxide? A 1320 B 438 C 9.61 D 146 E 1470

Answer 1

146 mL

Step-by-step explanation:

Step 1: Write the balanced equation

H₃PO₄ + 3 NaOH ⇒ Na₃PO₄ + 3 H₂O

Step 2: Calculate the reacting moles of sodium hydroxide

119 mL of 0.315 M NaOH react.

`0.119L * (0.315mol)/(L) = 0.0375mol`

Step 3: Calculate the reacting moles of phosphoric acid

The molar ratio of H₃PO₄ to NaOH is 1:3. The reacting moles of H₃PO₄ are 1/3 × 0.0375 mol = 0.0125 mol.

Step 4: Calculate the reacting volume of phosphoric acid

0.0125 moles of H₃PO₄ are in a 0.0855 M solution.

`0.0125 mol * (1L)/(0.0855mol) * (1,000mL)/(1L) =146 mL`