Calculate ΔH° for the following unbalanced reaction using the data for the enthalpy of formation in the appendix. C2H2(g) + O2(g) –> CO2 (g) + H2O (g)

Given the enthalpy changes: A +B –> C ΔH= -35 kj/mol A + D –> E + F ΔH= 20 kj/mol F –> C + E ΔH= 15 kj/mol

Consider the reaction: B2H6(g) + 3O2(g) –>B2O3(s) + 3H2O(g)             ΔH = -2035 kJ Calculate the amount of heat released when each of the following amounts of diborane (B2H6) is burned A mixture of 20.0 g B2H6 and 10.0 g O2

Nitrogen has a greater first ionization energy than oxygen. What is the best explanation for this observation?

Five successive determinations of the density of an alloy gave the following results: 10.29 g/ml 9.95 g/ml 10.06 g/ml 9.89 g/ml 10.18 g/ml What value should be reported for the density of this alloy?

Which compound contains the highest percentage of magnesium by mass?

A 10.00 g sample of a compound containing only carbon, hydrogen, and oxygen forms 23.98 g of CO2 and 4.91 g H2O upon complete combustion. What is the empirical formula of the compound?

If the actual density of the liquid was 1.18 g/mL, calculate the absolute uncertainty.

Calculate the average density

MgCl2 is a strong electrolyte. If 17.16 g of MgCl2 is dissolved in 150.0 mL of solution: Calculate the concentration (molarity) of MgCl2