Part A What is the concentration of a NaOH solution if it requires 25.34 mL of N
ID: 542310 • Letter: P
Question
Part A What is the concentration of a NaOH solution if it requires 25.34 mL of NaOH to titrate 25.00 mL of 0.0500 M H2SO4 Answer = 0.0987 M Part B: Following the procedure in the lab manual, 1.4372 g of an impure Na2CO3 sample was dissolved in 250.0 mL of water. Then 25.00 ml of this solution was treated with 25.00 ml of 0.0500 M H2SO4 to react all the carbonate. The excess H was titrated to a light pink endpoint with 15.13 mL of the NaOH solution in part A. What is the % of Na2CO3 in the original sample? Answer: 37%Explanation / Answer
H2SO4 is a diprotic acid, thus, it produces 2 moles of H+ ion. Hence, the concentration of H+ ion that need to be neutrlize by NaOH = 2 x [H2SO4] = 2 x 0.05 = 0.1 M
SaVa = SbVb
Sa= concentration of acid= 0.1 M
Sb = concentration of base=?
Va= volume of acid=25 ml
Vb= volume of bae =25.34 ml
Thus,Sb = SaVa / Vb = (0.1M x 25ml) / 25.34 ml = 0.0987 M NaOH