1) Selenic acid (H2SeO4)(H2SeO4) forms when solid selenium dioxide reacts with gaseous oxygen and liquid water to form aqueous selenic acid.
Enter a balanced chemical equation for this reaction.



2) Balance each of the following chemical equations. Give your answer as coefficients separated by commas.
a) NiF2(aq)+Fe2(SO4)3(aq)→NiSO4(aq)+FeF3(s)
b) N2H4(l)→NH3(g)+N2(g)N2H4(l)→NH3(g)+N2(g)
c) HClO4(l)+P2O5(s)→Cl2O7(l)+HPO3(s)
d) Al(s)+FeSO4(aq)→Al2(SO4)3(aq)+Fe(s)




3) Calculate how many moles of NO2NO2 form when each quantity of reactant completely reacts via the following reaction: 2N2O5(g)→4NO2(g)+O2(g)
a) 2.0 mol N2O5
b) 7.4 mol N2O5
c) 15.4 g N2O5
d) 2.79 kg N2O5


4) Hydrobromic acid dissolves solid iron according to the following reaction: Fe(s)+2HBr(aq)→FeBr2(aq)+H2(g)
a) What mass of HBrHBr (in gg) would you need to dissolve a 3.3-gg pure iron bar on a padlock?
b) What mass of H2H2 would be produced by the complete reaction of the iron bar?


5) What mass of carbon dioxide is produced upon the complete combustion of 27.3 LL of propane (the approximate contents of one 5-gallon tank)? Assume that the density of the liquid propane in the tank is 0.621 g/mLg/mL.
a)