@X@user.full_name@X@ @GMU: SrO has a face-centered cubic uni…

@X@user.full_name@X@ @GMU: SrO has a face-centered cubic unit cell in which the O2- anions occupy corners and face centers, while the cations fit into the hole between adjacent anions. What is the radius of Sr2+ if the ionic radius of O2- is 140.0 pm and the density of SrO is 4.700 g/cm3?

John Schreifels @GMU: What is the total entropy change at 25…

John Schreifels @GMU: What is the total entropy change at 25oC for the reaction below, if the standard entropies of reactants and products are So (C(gr)) = 5.74 J/mol*K, So (H2(g)) = 130.68 J/mol*K, and So (C8H8(g)) = 345.2600 J/mol*K and the heat of formation of C8H8(g)) is 147.8500 kJ/mol.8C(gr) + 4H2(g) → C8H8(g)

@X@user.full_name@X@ @GMU: How much energy in kJ is released…

@X@user.full_name@X@ @GMU: How much energy in kJ is released to form one mole of 123Sb from protons, electrons, and neutrons if the nucleus has a mass of 122.904216 amu? The masses of the proton, electron and neutron are 1.00728 amu, 0.000549 amu and 1.00867 amu, respectively.

@X@user.full_name@X@ @GMU: NO2 at 354°C decomposes to form N…

@X@user.full_name@X@ @GMU: NO2 at 354°C decomposes to form NO and O2 according to second order kinetics (see reaction below). The half-life for this reaction was measured to be 1.71e2 s when the initial concentration of NO2 was 3.25e-3 M. What is the rate constant for this reaction?2NO2(g) → 2NO(g) + O2(g)

@X@user.full_name@X@ @GMU: What is the potential of a cell a…

@X@user.full_name@X@ @GMU: What is the potential of a cell at 25oC for which the reaction below applies, if the molar concentrations of Sn2+(aq) and H+ are 0.100 M and 2.18e-4 M, respectively? The H2(g) pressure is 1 atm at 25oC.2H+(aq) + Sn(s) → Sn2+(aq) + H2(g) Ecoell = 0.140 V