How many molecules of water are produced when 8.93 * 1023 molecules of oxygen are reacted with excess hydrogen gas in the reaction below?
2H2 + O2 → 2H2O

Which of the following elements is a representative element? a. chromium (cr) b. aluminum (al) c. mercury (hg) d. silver (ag)

Both 1,2−dihydronaphthalene and 1,4−dihydronaphthalene may be selectively hydrogenated to 1,2,3,4−tetrahydronaphthalene. one of these isomers has a heat of hydrogenation of 101 kj/mol (24.1 kcal/mol), and the heat of hydrogenation of the other is 113 kj/mol (27.1 kcal/mol). match the heat of hydrogenation with the appropriate dihydronaphthalene.

#20 which type of bond is formed when bases pair in dna? ionic bond covalent bond coordinate bond hydrogen bond