Free AP Chemistry Exam Question and Answers

Question 1

To produce 127 g of copper, how many moles of electrons must be transferred?

Accepted Answer

two mole of electrons

Answer

one mole of electrons

Answer

three mole of electrons

Answer

four mole of electrons

Question 2

The electronegativity of nitrogen is comparable to that of phosphorus and oxygen. Which of the following best sums up how the three values relate to one another?

Accepted Answer

The value for nitrogen is less than that for oxygen because nitrogen has a lower effective nuclear charge, but it is higher than that for phosphorus since nitrogen is smaller.

Answer

The value for nitrogen is higher than that for oxygen because nitrogen has more valence electrons than phosphorus, but it is lower than that for phosphorus because nitrogen has fewer protons.

Answer

The value for nitrogen is higher than that for oxygen due to nitrogen's higher effective nuclear charge, but lower than that for phosphorus due to nitrogen's larger size.

Answer

Because nitrogen possesses fewer electrons than phosphorus but fewer than oxygen due to nitrogen's smaller size, the value for nitrogen is bigger than that for phosphorus.

Question 3

What, if any, effects may an increase in sodium hydroxide concentration have on the graph if done before repeating the titration?

Accepted Answer

The equivalence points would be reached with less volume of NaOH added.

Answer

The pH values at the equivalence points would increase.

Answer

The slope of the equivalence points would decrease.

Answer

The graph would not change at all.

Question 4

What happens to the equilibrium constant when ΔT increases, and why?

Accepted Answer

The equilibrium constant decreases because the equilibrium shifts to the left.

Answer

The equilibrium constant increases because more products are created.

Answer

The value for the equilibrium constant is unaffected by temperature and will not change.

Answer

The equilibrium constant increases because the rate of the forward reaction increases.

Question 5

A neutral atom of chlorine has a first ionization energy of 1.25 MJ/mol, while a neutral atom of argon has a first ionization energy of 1.52 MJ/mol. How would those numbers compare to the first ionization energy of a neutral potassium atom?

Accepted Answer

Since potassium's valence electron is further from the nucleus than those of either chlorine or argon, it would be less than both.

Answer

Since a potassium atom is smaller than an atom of either chlorine or argon, it would be more than both.

Answer

Because potassium has a higher nuclear charge than either chlorine or argon, it would be greater than both.

Answer

With more electrons in potassium, they oppose one another more potently and require less energy to remove one, thus it would be less than both.

Question 6

The gases in the container would vary from ideal conditions the greatest under which of the following circumstances, and why?

Accepted Answer

Low temperatures, because the intermolecular forces between the gas molecules would increase

Answer

Low pressures because the gas molecules would be spread far apart

Answer

High temperatures, because the gas molecules are moving too fast to interact with each other

Answer

High pressures because the gas molecules will be colliding frequently

Question 7

Which of the following is supported by a review of mass spectrometry data?

Accepted Answer

The existence of isotopes

Answer

Ionization energy trends within the periodic table

Answer

The common oxidation states of elements

Answer

Atomic size trends within the periodic table