Which element in the third period is best represented by the six successive ionization energies: IE1 = 737 IE2 = 1450 IE3 = 7731 IE4 = 10 545 IE5 = 13 627 IE6 = 17 995 ?

A sulphuric acid solution containing per liter of the solution has a density of . (Note:  ; ). Calculate the molarity.

Nitrogen dioxide reacts with water to form nitric acid and nitrogen monoxide according to the equation:
3NO2(g)+H2O(l)→2HNO3(l)+NO(g)

Suppose that 4.5 mol NO2NO2 and 0.40 mol H2OH2O combine and react completely. Which reactant is in excess?

Give the IUPAC name for each of the following

What is the IUPAC name for CH₃CHClCH(CH₃)CH₂CH₂CH₂CH₂Br?
 A) 1-bromo-6-chloro-5-methylheptane
 B) 7-bromo-2-chloro-3-methylheptane
 C) 1-bromo-6-chloro-5,6-dimethylhexane
 D) 6-bromo-1-chloro-1,2-dimethylhexane

The element oxygen was prepared by Joseph Priestley in 1774 by heating mercury(II) oxide: HgO(s) ® Hg(l) + ½O₂(g), DH° = 90.84 kJ/mol.

Estimate the temperature at which this reaction will become spontaneous under standard state conditions.

S°(Hg) = 76.02 J/K · mol

S°(O₂) = 205.0 J/K · mol

S°(HgO) = 70.29 J/K · mol