A Certain Rust Remover Containing Phosphoric Acid Has a Density

Multiple Choice

A certain rust remover containing phosphoric acid has a density of 1.685 g/mL.Titration of a 59.3 mL sample of the rust remover requires 1.40 L of 1.86 M NaOH to completely react with the acid to form sodium phosphate.What is the mass percent H₃PO₄ (98.0 g/mol) in the rust remover?

A) 14.6%
B) 19.8%
C) 39.1%
D) 69.7%
E) 85.1%