11 (a) Define a buffer solution (b) What are the components of (i) an acidic buffer ? (ii) a basic buffer ?

Calculate the pH of the resulting solution if 32.0 mL of 0.320 M HCl(aq) is added to 37.0 mL of 0.320 M NaOH(aq).

7.  The separate samples of nitric and acetic acids are both titrated with a 0.100 M solution of NaOH(aq). (Y) 25.0mL of 1.0 M HNO3(aq)                      (Z) 25.0 mL of 1.0 M CH3COOH(aq)   Determine whether each of the following statements concerning this titration is true or false. (A) A larger volume of NaOH(aq) is needed to reach the equivalence point in the titration of HNO3 (B) The pH at the equivalence point in the HNO3 titration will be lower than the pH at the equivalence point in the CH3COOH titration (C) Phenolphthalein would be a suitable indicator for both titrations Group of answer choices a.) A) False B) True C) True b.) A) False B) False C) True c.) A) False B) True C) False d.) A) True B)True C)True

42. A buffer is prepared using acetic acid, CH3COOH, (a weak acid, pKa = 4.75) and sodium acetate, CH3COONa (which provides acetate ions, the conjugate base), according to the following proportions:   Volume of CH3COOH(aq):   139.0 mL Concentration of CH3COOH(aq):  1.103 M   Volume of CH3COONa(aq):  127.0 mL Concentration of CH3COONa(aq):  1.259 M   Calculate the pH of this buffer after the addition of 20.00 mL of 3.00 M sodium hydroxide, NaOH, a strong base.     4.38     5.90     4.69     4.81     5.12

The acid-base indicator "Thymol Blue" has two transition ranges as listed below (with the corresponding acid dissociation constants): 7. Ka AcidColour BaseColour Thymol Blue 1 Thymol Blue 2 2.24 x 102 Red Yellow 1.26 x 10 Yellow Blue What colour would you expect it to be at the following pH values? Briefly justify your answers. (a) (b) (c) (d) 0.9 5.2 7.8 10.7

Calculate the pH of the resulting solution if 31.0 mL of 0.310 M HCl(aq) is added to 41.0 mL of 0.310 M NaOH(aq).