assume an activity coefficient of 1 for all substances and no effect of ionic strength. eliminate terms in quadratic solutions for [h_{+}] only if the weak acid is dissociated < 5%

a. in a hospital laboratory, a 10.0 ml sample of gastric juice obtained several hours after a meal was titrated with 0.1 m naoh to neutrality; 7.2 ml of naoh was required. the patient's stomach contained no indigested food or drinks, thus assume no buffers were present. what is the ph of the gastric juice?

b. lactic acid is produced and builds up in muscles during intense exercises and causes painful, sore muscles. what is the ph of 0.6 mm lactic acid, pka = 3.86.

c. what is the ph of a mixture of equal volumes of 0.6 mm hcl and 0.4 mm naoh?

d. what is the ph of a mixture of equal volumes of 0.6 mm lactic acid and 0.4 mm naoh?

e. if the concentrations of hcl and naoh are tripled in part c, by what factor will the ph be changed?

f. if the concentrations of lactic acid and naoh are tripled in part d, by what factor the ph be changed?

g. what is the rationale for the observed differences in ph as a function of increasing hcl and lactic acid concentrations?