The red and yellow diamond in a NFPA sign represents what?

Based on the equation and the information in the table, what is the enthalpy of the reaction?

The following reaction shows sodium carbonate reacting with calcium hydroxide. na2co3 + ca(oh)2 → naoh + caco3 how many grams of naoh are produced from 20.0 grams of na2co3? (molar mass of na = 22.989 g/mol, c = 12.01 g/mol, o = 15.999 g/mol, ca = 40.078 g/mol, h = 1.008 g/mol) 12.2 grams 15.1 grams 24.4 grams 30.2 grams

What is the ph of a 0.0010 m hno3? 1.0 3.0 4.0 5.0