Question

Determine which weak acid is the best option to make a buffer at the specified pH of 3.00.

***formic acid, ?a=1.77×10−4, 2.00 M

propionic acid, ?a=1.34×10−5, 3.00 M

phosphoric acid, ?a=7.52×10−3, 1.00 M

acetic acid, ?a=1.75×10−5, 5.00 M

Determine which conjugate base is the best option to make a buffer at the specified pH.

sodium dihydrogen phosphate monohydrate, NaH2PO4⋅H2O

***sodium formate, HCOONa

sodium acetate trihydrate, CH3COONa⋅3H2O

sodium propionate, CH3CH2COONa

The final volume of buffer solution must be 100.00 mL and the final concentration of the weak acid must be 0.100 M.

Based on this information, what mass of solid conjugate base should the student weigh out to make the buffer solution with a pH of 3.00?

Based on this information, what volume of acid should the student measure to make the buffer solution?

Answer 1

pageof Answen informaton, 9svern According to the to find the folloesing pioblems Let, tor choosn he bt Conbtralion, -the pka value must be closest to the p is 3.00 Gtven, heak acid Pka 3.152 Ka t6 for mfc acid ka 3ux1 Pka : ५.४7२४ Propfonic actd ka x Pla u.569 acec acid ka 2xD Pkaz .123 Phasphasic atd Congugate base sadtum formate HCOONa Sadium paopionate CHgCHcooa 30dium accate thydwate CH2 CooNa 31h0 sadtam hyho gn phospheie monohyhale atr Ho

fage:02 -thenefoe PoYmic actd hai tu pka value closest to pf. 8.00 formic acid Sodium -fomate ehoose ungendeson pH plat log acid acid -O5 acid -o52 Cactd (baue) fadd nal Concentvation actd 4e butu soluton ftnal volume Aohat volume acid measured oal be x ml volume o x (l00-r) 9.00M x oom

page:03 a xx oo mL acid Sml .. volume Achat ma o solid Confuqtc lcase Lot base Cacid base o.I X oHT H rhen sodium -format 683mol moleculan wetght Hdes o base soqpiod O.0011moles bae ouquicud : oo0Hnt x 689/met O.a036 ma of base suquod