1. For the following reaction:

2 SO2 (g) + O2 (g) → 2 SO3 (g) ΔHf SO3 (g) = −397.77 kJ/mol

a. Calculate the heat change for the reaction of 37.8 g sulfur dioxide in excess oxygen.

b. Will the temperature of the surroundings increase or decrease as a result of this reaction? Why?

The first element on the periodic table of elements is carbon. a. true b. false

As changes in energy levels of electrons increase, the frequencies of atomic line spectra they emit

)benzene and toluene form nearly ideal solutions. consider an equimolar solution of benzene and toluene. at 20 °c the vapour pressures of pure benzene and toluene are 9.9 kpa and 2.9 kpa, respectively. the solution is boiled by reducing the external pressure below the vapour pressure. calculate (i) the pressure when boiling begins, (ii) the composition of each component in the vapour, and (iii) the vapour pressure when only a few drops of liquid remain. assume that the rate of vaporization is low enough for the temperature to remain constant at 20 °c.