1.Suppose you are asked to prepare a buffer with pH = 7.40. Whatacid would be the best choice to prepare this buffer? Given that you had 500.0 mL of the acid,what mass of the corresponding sodium salt of the conjugate base would be requiredto make the buffer? What is the chemical formula of the sodium salt chosen? Assume the volume does not change on addition of the sodium salt.
2. Suppose that you add 5.0 mL of 0.10M H2SO4 to a 20.0 mL solution of 0.10M NH3. Will the addition of the H2SO4 yield a buffer? Calculate the pH of the resulting solution. Kb for NH3 = 1.8 x 10^(-5)
3. 25.00 mL of 0.100 M NH3 is titrated by 0.100 M HCl. Methyl redcan be used as an indicator for the titration.
a.What volume of HCl is required to reach the equivalence point?
b.Calculate the pH before any addition of HCl.
c.Calculate the pH after adding 10.00 mL of HCl.
d.Calculate the pH at the equivalence point.
e.Calculate the pH after adding 40.00 mL of HCl.
f. Use the pH values obtained in steps b-e above to make a plot of the titration curve. Label the calculated pH values on the plot. Label the buffer region and the equivalence point. Was the choice of Methyl red indicator a good choice for this titration? Briefly explain.