Find the enthalpy of the following reaction at 25 °C using average bond enthalpies. CH3CH3 (g) + 7/2 O2 (g) → 2 CO2 (g) + 3 H2O (g)

Average bond enthalpies (kJ/mol): E(C–C)=347, E(C–H)=413, E(O= O)=498,

E(C= O)=804, E(O–H)=463

Which class of molecules functions as chemical signals? hormones water carbohydrates proteins

20 pts ‼️ an unmanned spacecraft travels to mars. mars has a lower strength of gravity than earth. where in the image is the spacecraft’s weight the greatest?

3.09 lab: reaction of metals 1 which combinations of substances resulted in a chemical change? for each metal that participated in a chemical change, write the type of metal it is, based on your examination of the periodic table. were there any metallic compounds that did not react with either the acid or the base? write the type of metal, based on your examination of the periodic table. make a general statement about the reactivity of the metals in this experiment.