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

146 mL

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.

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.

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.  

answers: to make sure that all of the broken pieces of tablet were added to the water, to allow for fair comparison of all three trials, with different particle sizes to avoid experimental error