aqua vs hydric acid

aqua

noun
  • The compound water. 

  • A shade of colour, usually a mix of blue and green similar to the colour turquoise. 

adj
  • Of a greenish-blue colour. 

hydric acid

noun
  • One of several systematic acid names for water, H₂O. 

How often have the words aqua and hydric acid occurred in a corpus of books? (source: Google Ngram Viewer )