4. A 500-mg sample of each mixture was analyzed for its alkaline content using 0.1025MHCl via double indicator methan Which of the following mixtures contains NaHCO3 ? a. Mixture 2 and 3 c. Mixture 4 and 5 b. Mixture 2 and 4 d. Mixture 1 and 2 15. Calculate the pH of 3.5103MHNO3. a. 3.00 b. 2.46 c. 1.54 d. 3.46