Question

The concentration of a phosphoric acid solution is determined by titration against a 0.00215 g sample of pure NaOH using phenolphthalein indicator. What is the concentration of the phosphoric acid solution if it required 25.12 mL of phosphoric acid to titrate the NaOH sample when dissolved in water

Answer 1

To find the concentration of the phosphoric acid solution, we can use the concept of titration. The equation for the reaction between phosphoric acid (H3PO4) and sodium hydroxide (NaOH) is H3PO4 + NaOH -> NaH2PO4 + H2O. Given that 25.12 mL of phosphoric acid was required to titrate the 0.00215 g sample of NaOH, we can calculate the concentration of the phosphoric acid solution by equating the moles of NaOH and moles of H3PO4.

Step-by-step explanation:

To find the concentration of the phosphoric acid solution, we can use the concept of titration. The equation for the reaction between phosphoric acid (H3PO4) and sodium hydroxide (NaOH) is:

H3PO4 + NaOH → NaH2PO4 + H2O

Given that 25.12 mL of phosphoric acid was required to titrate the 0.00215 g sample of NaOH, we can calculate the concentration of the phosphoric acid solution using the equation:

moles of NaOH = moles of H3PO4

From here, we can determine the concentration of the phosphoric acid solution in mol/L (M) or molarity.