The enthalpy of combustion for octane (C8H18(l)), a key component of gasoline, is –5074 kJ/mol. The reaction equation is: C8H18(l) + 12.5O2(g) →8CO2(g) + 9H2O(g). What is the ΔHf for this reaction?

Which of the following pairs of elements belong to the same groupa. h and he b. li and bec. c and pb d. ga and ge

An excess of lithium oxide undergoes a synthesis reaction with water to produce lithium hydroxide li2o+h2o→2lioh if 1.05 g of water reacted, what is the theoretical yield of lithium hydroxide? a) 5.83 x 10–2 g lioh b) 1.17 x 10–1 g lioh c) 2.79 x 100 g lioh d) 1.40 x 100 g lioh

Which sentence about particles in matter is true? a. atoms are present in solids and liquids but not in gases. b. the particles of matter are in constant motion. c. the same kinds of atoms are found in different elements. d. when a solid changes to a liquid, the sizes of the particles change.