What is the standard enthalpy change for the reaction?  2NH3(g)N2H4(l) + H2(g)N2H4(l) + O2(g)N2(g) + 2H2O(g)               ΔH°1 = –543 kJ·mol–12H2(g) + O2(g)2H2O(g)                              ΔH°2 = –484 kJ·mol–1N2(g) + 3H2(g)2NH3(g)                               ΔH°3= –92 kJ·mol–1   Data sheet and Periodic Table

Which line corresponds to a process that requires an input of energy?           Data sheet and Periodic Table

Which molecule is polar?   Data sheet and Periodic Table

Aquamarine is a mineral called Beryl.  What is the empirical formula of aquamarine if it contains 3.3% beryllium, 6.6% aluminum, 54.9% silicon and 35.2% oxygen by mass?  Data sheet and Periodic Table

In which reaction is carbon reduced?   Data sheet and Periodic Table

In the compound (NH4)2S2O3, which element is present in the largest percent by mass?  Data sheet and Periodic Table

A 10 gram sample of which substance contains the greatest number of hydrogen atoms?   Data sheet and Periodic Table

In a 10.0 L vessel at 100.0 oC, 10.0 grams of an unknown gas exert a pressure of 1.13 atm.   What is the gas? Data sheet and Periodic Table

Which calculation can be used to determine the standard enthalpy of formation of NO(g)?N2(g) + 2O2(g)2NO2(g)              ΔH°1NO(g) + ½O2(g)NO2(g)              ΔH°2   Data sheet and Periodic Table

Which gas, helium or argon, effuses faster under the same conditions and by how much? Data sheet and Periodic Table