Question

|-/0.5 points GVSUCHEM116V2 14.6.3.P004. My Notes Calculating the pH of a Buffer Solution To prepare a buffer you weigh out 9.00 grams of KNO2 and place it into a 500.00 mL volumetric flask. To this flask you add 18.0 mL of 3.80 M HNO, and then fill it about halfway with distilled water, swirling to dissolve the contents. Finally, the flask is filled the rest of the way to the mark with distilled water. Measured volume of the weak acid Solid salt of the conjugate base Acid H2CO3 HCN Ka 4.3 X 107 4.9 X 1010 4.6 X 104 6.5 X 105 HNO2 С6Нѕсоон Volumetric Flask What is the pH of the buffer that you have created?

Please answer within 40 minutes for when the question is due, thank you!

Answer 1

Solution As per given in the question mass of KNO2 used a gooogon Concentration of HNO2 = 3.80m Volume of Honga 18.0ml Volume of soluton = sooml No.of moles of KNO= mass = 9 molar mass 85T-0110576 Molarity of kno z moles of KNO2 x103 0.10576 xl.no Volone (inmi) moles of HNO2 useda molarityx volume (inL) = 3.80 X 18x163 - 0.0684 Molarity of Halos in resultant Solution = moles 0.0684 Volume line 320X163 0.13689 ph of Buffer ( HNO2 / kNos): 7 Exlu00_0:211574 Svo ph= pka + lookno] Ipka= -log ka L. -- log 4.6X164 = 3.337 pH3.337 + log0.2015 = 3.337+ 0.1892 pu = 3.526