Respuesta :

JoshEast

Answer: 31.61 %

Explanation:

% phosphorus by mass

            = (mass of phosphorus ÷ mass of phosphoric acid) × 100%

            = (30.974 g/mol ÷ 97.994 g/mol) × 100%

          =  31.61 %

∴ percent of phosphorus by mass in phosphoric acid 31.61%.