Question

with everything going on in the world, i can no longer go to tutoring to get help with chem so if you dont mind explaning your solutions i would be grateful

13. If 400. mL of 0.100 M CH,COOH and 200. mL of 0.100 M NaCH,COO solutions are mixed, what is the pH a work opp.4L of the resulting solution? CH3COOH : 1.5*10 a. 3.09 Na Chloo o.run..2 b. 3.33 c. 3.78 d. 4.44 e. 4.60 14. A buffer solution is prepared by mixing 250. mL of 1.00 M CH,COOH with 500 mL of 0.500 M calcium acetate, Ca(CH,COO). Calculate the pH. a. 5.36 b. 5.05 c. 4.74 d. 4.58 e. 4.40

Answer 1

13 0.100M CH2COOH ; 400 mL = (400 x 0.100) 40 m.moll 0.100 M C113C00NG; 200 mL (200 %0.100) . = 20 m. mol. The total volume is same for both case). As the mixture of CH₂ cool and CM₂ Coolta. formed acidic buffer, so, according to Henderson equation, pit. = pka + log I Band I = -log('8 x 10+5) +dog (20) = 4:745 +log (+) = 4:44

13. answer - (d)

14 1.00M CHz Coolt; 250 mL = (250 x1.00) = 250 m. mol. 0.500 M Ca(CH2C00)2 , 500 mL = (500X0.500) = 250 m. mol. Total volume is same for both case, but the salt form 2 Conjugate base on it's dissociation, Therefore, Fconjugate base) = (250x2) = 500 m. med The acidic buffer is formed due to the mixing of the salt and the weak acid. So, pH = pkat log Lenjugate Love] ng Tacid =4.745 +log( 250) = 4.745 + log 2 = 5.0.5

14. answer - (b)