Which weak acid would be best to use when preparing a buffer solution with a pHpH of 8.50?8.50? an acid with Ka=2.0×10−10Ka=2.0×10−10 an acid with Ka=0.00050Ka=0.00050 an acid with Ka=6.3×10−6Ka=6.3×10−6 an acid with Ka=4.0×10−5Ka=4.0×10−5 an acid with Ka=3.3×10−9Ka=3.3×10−9 an acid with Ka=5.0×10−7

Find the ph of a buffer solution that is made by mixing 30ml of 1M NaA and 30ml of 1M HA. Find the ph when 2ml of 1M HCl is added to 30ml of this buffer solution. Given (Ka = 2.11*10^-5)

What is the pH at the equivalence point when you mix 20mL of 0.1M of some acid with 40mL of 0.05M of some base? Ka = 1.74 * 10^-4

A diprotic acid is titrated with a strong base. The pH at the first half-equivalence point is (3.69x10^0). The pH at the second half-equivalence point is (8.9000x10^0). What is the value of ka2? Enter your answer using 3 significant figures.

Ethyl orange changes from red at 3.4 to blue at 4.8. What is the approximate Kin value for ethyl orange? 1.3E4 1.6E -5 4.1 4.0E-4 7.9 8E-5 What form is the indicator in if the pH is 6? In-, the deprotonated form Hln, the protonated form a mixture of both Hin and In -

A buffer solution is prepared using a weak acid and its conjugate base. If the weak acid concentration is 0.746 M and pH is 5.85, what is the concentration of the conjugate base? (Ka=1.76x10-6)

Which is true about buffer solutions? -they hold the pH close to the pKa  -they contain comparable moles of a weak acid and a strong base  - they hold pH constant at pH=7  -they prevent acids and bases from reaching equilibrium  -they hold the pH close to the equivalence point pH

Which of the following acid/base pairs would not make a good buffer system? H2PO4-/ HPO42- HSO3-/Na2SO3 H2CO3/H2CO2- NH4+/NH3 HNO2/NO2-

What is the pH of an aqueous solution containing 75.0 mL of a 0.15M HNO2 solution and 45.0 mL of a .25M KNO2? What is the pH of this solution after 10.0 mL of a 0.20M solution of KOH is added? How would you categorize this problem (i.e. strong acid or weak acid titrated by strong base or weak base, buffer)?

Lemons get their sour flavor from citric acid (Ka = 7.4 x 10-4) a fresh squeezed lemon can have a citric acid concentration of 0.3 M and produce 20 mL. What is the pH at the equivalence point?