Answer to Question #210237 in General Chemistry for Ojeda

Question

Direction: Solve the following problem. Show your complete solution and the chemical equation. (5 bonus points)

A buffer solution of pH 7.30 will be prepared from 50.00 mL solution of 0.075 M NaH2PO4 (Ka = 6.3 10-8). How many grams of NaH2PO4 must be dissolved in the solution to get the desired pH? (molar mass of NaH2PO4 = 119.0g/mol)

Answer 1

7.3

Molar Mass of NaH2PO4 = 119.98 g/mol

0.075 ×119.98= 8.999g

= 6.3× 10^-8×8.999

= 56.69g