Ethyne (c2 h2 (g), mc032-1.jpghf = 226.77 kj/mol) undergoes complete combustion in the presence of oxygen to produce carbon dioxide (co2 (g), mc032-2.jpghf = –393.5 kj/mol ) and water (h2 o(g), mc032-3.jpghf = –241.82 kj/mol) according to the equation below.

mc032-4.jpg

what is the enthalpy of combustion (per mole) of c2 h2 (g)?
–2511.2 kj/mol
–1255.6 kj/mol
–862.1 kj/mol
–431.0 kj/mol

How does a large body of water, such as the ocean, influence climate?

How could a student test the effect of removing heat from a gas that is stored in a sealed container? what must occur in order for matter to change states?

Phosphoric acid is a triprotic acid ( =6.9×10−3 , =6.2×10−8 , and =4.8×10−13 ). to find the ph of a buffer composed of h2po−4(aq) and hpo2−4(aq) , which p value should be used in the henderson–hasselbalch equation? p k a1 = 2.16 p k a2 = 7.21 p k a3 = 12.32 calculate the ph of a buffer solution obtained by dissolving 18.0 18.0 g of kh2po4(s) kh 2 po 4 ( s ) and 33.0 33.0 g of na2hpo4(s) na 2 hpo 4 ( s ) in water and then diluting to 1.00 l.