Question

Review Constants Periodic You have to prepare a pH 3.65 buffer, and you have the following 0.10M solutions available: HCOOH, CH3COOH, H3PO4, HCOONa CH3COONa, and NaH2PO4 Submit Previous Answers ✓ Correct Part B How many milliliters of HCOOH and HCOONa would you use to make approximately a liter of the buffer? Express your answers using two significant figures. Enter your answers separated by a comma. EVO A£¢ N O P ? VHCOOH, VHCOONa = ml Your submission doesn't have the correct number of answers. Answers should be separated with a comma. No credit lost. Try again. Submit Previous Answers Request Answer

Answer 1

Solution oka (HCOOH) 3.75 triven, pH= 3.65 [hcoor = [hcoona] =0.109 Volume = 12 a 1000 mL By Henderson Hasselbalch equation o pH2 pka + lug [salt I 3.65 = 3.75 + long [salt] Cacid 3.65-3.75 = log Chcoona] [Hook] » [hcoona] =10-01 = 0.9943 1 [ncoor] Let x ml be the amount of H2OOM then amount of HCOONa = 0.79430 mL from above ratio According to question x + 0.74 3x - 1000ml 1.7943a 2 1000 mL >> x= 557.31 560mL

Thus, Volume of HCOOH in buffer = x=(560ml) . volume of HcOona in buffer = 1000-560 = 1440 mL Vacoon, Uncoona = 1560,440 mL Answer