ap chem semester 1 MCQs

the students determined that the reaction produced 0.010 mol of Cu(NO3)2. based on the measurement, what was the percent of Cu by madd in the original 2.00 sample of the mixture?

B: 32%

the first five ionization energies of an unknown element are listed in the table above. which of the following statements correctly identifies the element and cites the evidence supporting the identification?

B: Al because the large difference between the third and forth ionization energies

the photoelectron spectra for H and He are represented above. which of the following statements best accounts for the fact that the peak on the He spectrum is farther to the left and higher than the peak on the H spectrum?

B: He has a greater nuclear charge than H and an additional electron in the same energy level

the mass spectrum of an average sample of a pure element is shown in the figure above. which of the following is the identity of the element?

B: Zr

the diagram above represents the photoelectric effect for a metal. when the metal surface is exposed to light with increasing frequency and energy of photons, electrons first begin to be ejected from the metal when the energy of the photons is 3.3x10^-19 J. using the wavelength information above, what is the color of the light?

B: orange

the compound CCl4 is nonflammable and was once commonly used in fire extinguishers. on the basis of periodic properties which of the following compounds can most likely be used as a fire-resistant chemical

C: CBr4

based on coulomb's law and the information in the table above, which of the following anions is most likely to have the strongest interactions with nearby water molecules in an aqueous solution?

C: S2-

the ionization energies of an unknown element, X, are listed in the table above. which of the following is the most likely empirical formula of a compound formed from element X and phosphorus, P?

C: X3P2

the photoelectron spectra above show the energy required to remove the 1s electron from a nitrogen atom and from an oxygen atom. which of the following statements best accounts for the peak in the upper spectrum being to the right of the peak in the lower spectrum?

D: nitrogen atoms have a smaller nuclear charge than oxygen atoms

which of the following correctly compares periodic properties of two elements and provides an accurate explanation for that difference?

D: the atomic radius of Cl is smaller than that of S because Cl has a larger nuclear charge than S does

a sample of s solid labeled as NaCl may be impure. a student analyzes the sample and determines that it contains 75 percent chlorine by mass. pure NaCl contains 61 percent chlorine by mass. which of the following statements is consistent with the data?

D: the sample contains NaCl and LiCl

which of the following represents the ground state electron configuration for the Mn3+ ion? (atomic number Mn=25)

A: 1s2 2s2 2p6 3s2 3p6 3d4

on the basis of the data provided above, the gas in container 3 could be

A: CH4

if a pure sample of an oxide contains 40% sulfur and 60% oxygen by mass, then the empirical formula of the oxide is

A: SO3

based on the periodic trends and the data in the table above, which of the following are the most probably values of the atomic radius of the first ionization energy of potassium, respectively?

B: 242pm, 419 kJ/mol

the complete photoelectron spectra of neutral atoms of two unknown elements, X and Y, are shown above. which of the following can be inferred from the data?

C: element Y has a greater nuclear charge

beta-carotene is an organic compound with an orange color. the diagram above shows the ultraviolet spectrum of beta-carotene. which of the following statements is true about the absorption bands in the spectrum?

C: the two main absorption bands are associated with transmission in electronic energy levels. the band in the region corresponding to shorter wavelengths shows a lower absorbance than the band in the region corresponding to longer wavelengths

which of the following best helps to explain why Na is more reactive than Mg is?

D: the first ionization energy of Na is less than that of Mg