The standard enthalpy of formation of B2O3(s) is -1263.6 kJ/mol. Use this information, and the table of standard enthalpies of formations e
to find the (delta)H°f for one mole of B5H9(1).

(Delta)H = -9036.6 kJ/mol
2 BgH9(1) + 12 O2(g) -->5 B2O3(s) + 9 H2O(1)

i do not get it   at all

im pretty sure its b

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.

yes

ya te ayud espera