Consider the reaction

B (s) + 32O2 (g) →B2O3 (s), ΔH = - 1270kJ

What will ΔH be for the reaction if it is reversed?

Express your answer with appropriate units.

Calculate the standard molar enthalpy for the complete combustion of liquid ethanol (C2H5OH) using the standard enthalpies of formation of the reactants and products. C2H5OH (l) + 3 O2 (g) = 2CO2 (g) + 3 H2O

Which statement best explains how isotopes can have different masses and still be the same element? A. The quantity of protons identifies the element but changes if the mass of the isotope differs from what is shown on the periodic table. B.

Which of following describe (s) a way in which radio waves can carry energy? A. through rock layers, from a source, to a reflector, and then to a receiver B. through the Earth's atmosphere, from a broadcast tower to a receiver C. all of these

Which of the following is a negatively charged particle? A. proton B. electron C. coulomb D. neutron

Brian has an object suspended in the air. It has a mass of 100 kg and is 25 meters above the ground. What is the object's potential energy

Which scientist developed the quantum mechanical model of the atom? a. Albert Einstein c. Niels Bohr b. Erwin Schrodinger d. Ernest Rutherford

How are metal atoms arranged according to metallic bonding?

why would it not be necessary to heat the air in the balloon as much if the air outside the balloon is colder?

Are the relationships in group 7a consistent with the periodic trend that you have been studying

Which is not a property of a mineral? A. cleavage B. reflection C. magnetism D. color