Name: phosphoric acid
* IUPAC
CAS Number: 7664-38-2
Chemical Formula: H₃PO₄
Molar Mass: 97.995181 g
Mass Percent: H 3.0856 %; P 31.607 %; O 65.306 % 

• inorganic

• "needed in the manufacture of a multitude of products, including fertilizers and detergents, baking powder, and various food products" 1

• "9th most produced chemical in the United States in 1995 - 11.5 megatonnes." 2

• "9th most produced chemical in the United States - 20.95 billion pounds" 3

• "Phosphoric acid is used to make phosphate fertilizers and detergent preparations. The acid is also added to carbonated beverages to increase tartness." 4

3 Ca(OH)2 (aq) + 2 H3PO4 (aq) → 6 H2O (ℓ) + Ca3(PO4)2 (s) 8
Ca3(PO4)2 (s beta) + 3 H2SO4 (aq) → 2 H3PO4 (aq) + 3 CaSO4 (s) 9
Ca3(PO4)2 (s beta) + 3 H2SO4 (ℓ) → 2 H3PO4 (ℓ) + 3 CaSO4 (s) 10
3 NaOH (aq) + 1 H3PO4 (aq) → Na3PO4 (aq) + 3 H2O (ℓ) 11
P4O10 (s) + 6 H2O (ℓ) → 4 H3PO4 (aq) 12
PCl5 (ℓ) + 4 H2O (ℓ) → H3PO4 (aq) + 5 HCl (g) 13
2 H3PO4 (aq) + 3 CaCO3 (s) → Ca3(PO4)2 (s) + 3 H2O (ℓ) + 3 CO2 (g) 
2 H3PO4 (aq) + 3 MgCO3 (s) → Mg3(PO4)2 (s) + 3 H2O (ℓ) + 3 CO2 (g) 
2 H3PO4 (aq) + 3 Na2SO3 (s) → 2 Na3PO4 (aq) + 3 H2O (ℓ) + 3 SO2 (g) 

Wikipedia

(1) - Kotz, Treichel, and Weaver. Chemistry & Chemical Reactivity, 6th ed.; Thomson Brooks/Cole: Belmont, CA, 2006; p 1030.
(2) - Chem. Eng. News, 1995, 73 (26), p 39
(3) - Reisch, Mark S.; Top 50 Chemicals Production Turned Back Up in 1987. Chemical & Engineering News, April 11, 1988, pp 30-33.
(4) - Ebbing, Darrell D. General Chemistry 3rd ed.; Houghton Mifflin Company: Boston, MA, 1990; p 345.
(5) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.
(6) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.
(7) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.
(8) - Zumdahl, Steven and Zumdahl, Susan A. Chemistry 9th ed.; Brooks/Cole: Belmont, CA, 2014; p 131.
(9) - Swaddle, T.W. Inorganic Chemistry; Academic Press: San Diego, 1997; p 186.
(10) - Zumdahl, Steven and Zumdahl, Susan A. Chemistry 9th ed.; Brooks/Cole: Belmont, CA, 2014; p 133.
(11) - Ebbing, Darrell D. General Chemistry 3rd ed.; Houghton Mifflin Company: Boston, MA, 1990; p 140.
(12) - Ebbing, Darrell D. General Chemistry 3rd ed.; Houghton Mifflin Company: Boston, MA, 1990; p 222.
(13) - Zumdahl, Steven and Zumdahl, Susan A. Chemistry 9th ed.; Brooks/Cole: Belmont, CA, 2014; p 131.