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Solve the following problems while observing the proper number of significant figures. Show your solutions. Atomic Weights: H = 1.00 g/mol C = 12.00 g/mol N = 14.00 g/mol 0 = 16.00 g/mol Na = 23.00 g/mol CI = 35.45 g/mol Br = 79.90 g/mol 3. What is the pH of a solution of propionic acid (HC.H2O2; K. - 1.3 x 105) made by dissolving 55.0 g of HC4H2O2 in a 1.5 L solution? (4 pts) 4. A basic buffer solution of pH 8.1 is to be prepared. (a) Which among the given acids and their sodium salts below shall yield the best basic buffer solution? (2 pts) (b) What weights of the best acid and its salt must be dissolved to make a 1.00-L solution if the concentration of the acid is 0.50 M? (4 pts) Acid Salt K Hydroazoic acid HN3 NaN: 1.9 x 10-6 Hypochlorous acid HCIO Nacio 3.0 x 108 Hypobromous acid HBrO NaBro 2.5 x 100