AP Chemistry Practice (Interactive)

Which of the following electron configurations represents a ground-state atom with the highest first ionization energy in its period?

Which of the following correctly ranks the atoms Mg, Al, and Si in order of increasing atomic radius?

An element has the electron configuration [Kr] 4d10 5s2 5p3. What is the expected oxidation state of this element in its most stable compounds?

Which of the following compounds has the highest boiling point?

The Lewis structure of the sulfate ion (SO4^2-) shows the central sulfur atom bonded to four oxygen atoms. What is the formal charge on the sulfur atom when all bonds are single bonds?

A compound contains 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen by mass. What is its empirical formula?

The enthalpy of combustion of methane is -890 kJ/mol. When 0.50 mol of methane is burned completely in excess oxygen, how much heat is released?

Given the following reactions: (1) C(s) + O2(g) yields CO2(g), delta H = -393.5 kJ/mol; (2) CO(g) + 1/2 O2(g) yields CO2(g), delta H = -283.0 kJ/mol. Using Hess\'s law, what is delta H for the reaction C(s) + 1/2 O2(g) yields CO(g)?

A catalyst increases the rate of a chemical reaction by:

For the equilibrium N2(g) + 3 H2(g) <=> 2 NH3(g), delta H = -92 kJ/mol, which change will increase the yield of ammonia at equilibrium?