Acetic acid has pKa of 4.76. At which pH does it act as the best buffer? A. <<4.76 B. = 4.76 C. = 7.0 D. >> 7.0

the reagent potassium phosphate tribasic trihydrate (K3PO4*3H2O) and 1.1M HCl and 1.1 M NaOH. you need to make 1 liter of buffer that has 0.01 molar minimum buffer capacity to resist either 0.01 moles of strong base or strong acid at pH 7.2.   a. How many grams of potassium phosphate tribasic trihydrate are theoretically needed?   b.how many mL of HCL solution?   c. How many mL of NaOH solution? Please answer very soon will give rating surely All questions answers needed

2. A solution of pH 12 will contain a large concentration of (fill in) a. Cl- b. Na+ С. ОН- d. H+ ions. Buffers are substances that keep the pH of a solution stable. In blood, the main buffer system is carbonic acid-bicarbonate in which bicarbonate acts as the a. H+ suppressor b. H+ асceptor c. H+ donor d. H+ processor H,CO3 HCO,- + Looking at the above equation we can deduct that if an acidic solution is injected in the blood of a person, the above equilibrium will move to the a. right b. left The action of buffers in the blood is important to keep the pH stable around а. 7.4 b.7.0 с. 7.8 d. 6.8 In the human stomach, digestive enzymes require a high concentration of a. hydroxide ions b. protons c. cholesterol d.inositol for optimal function.

a. Calculate the number of moles of HCI(g) that must be added to 1.0 L of 1.1 M NaC,H3O2 to produce a solution buffered at pH = pK,. K. (HC,H3O2) = 1.8 x 10-6 Number of moles = mol b. Calculate the number of moles of HCI(g) that must be added to 1.0 Lof 1.1 M NaC,H3 O, to produce a solution buffered at pH = 4.20. KA(HC,H;O2) = 1.8 x 10-5 Number of moles = mol c. Calculate the number of moles of HCI(g) that must be added to 1.0 L of 1.1 M NaC,H3O2 to produce a solution buffered at pH = 5.00. K. (HC, H, O2) = 1.8 x 10-5 Number of moles = mol

9. How does the solubility of cach salt change? More soluble at Low or High pH? Added Added KF Added Ba(NOs)2 HCI a. BaF2 b. BaCO3 c. Ba(OH)2 d. FeF2 e. AgCI f. Pbl2 g. FeSO,

What is the hydroxide ion concentration in a solution that containing 0.50 mole of ammonium hydroxide and 0.05 mole of ammonium chloride per liter of solution? Since the pKb of ammonium hydroxide is 4.75? and What is the type of buffer solution? a- 1. 54 x 10-4 M. basic buffer b- 1.77 x 10-4 M. acidic buffer c- 1.77 x 10-4 M. basic buffer d- 1. 54x 10-4 M. acidic buffer الاختيارات b a O C d O

13

1. A buffer is prepared using 0.522 mol of NH4CI and 0.812 mol of NH3 to make 1.00 L of solution. What is the pH of the solution after adding 0.153 mol of NaOH. Assume that the volume change is negligible. The pKa of NH4Cl is 9.26. 2. A buffer is prepared using 0.636 mol of HO2C2H3 and 0.848 mol of NaO2C2H3 to make 1.00 L of solution. What is the pH of the solution after adding 0.137 mol of HCI. Assume that the volume change is negligible. The pKa of HO2C2H3 is 4.74.

A TRICINE buffer is made to a pH of 8.15 at 25 °C then warmed to 37 °C. The pH of the solution changes because the pK, changes. TRICINE has a pK, = 8.14 and a ApK/AT= -0.018 "C¹, Calculate the pH of the buffer at 37 °C. pH =

2. Determine the best answer on the follow:What buffer pH can be prepared from an arbitrary weak acid whose pKa is 7.20?a. pH 8.30b. pH 6.40c. pH 2.80d. pH 5.80 All salts are products of neutralization reactions between an acid and a base. Thus, all salts form a neutral solution when dissolved.a. Trueb. False