🧪AP Chemistry
1. Answer the following questions about titanium and its compounds.
A mass spectrum for a sample of titanium is shown in Figure 1. The spectrum is incomplete.
Figure 1. Incomplete mass spectrum for titanium (relative abundance vs. mass-to-charge ratio)
The percent abundances of the titanium isotopes shown in Figure 1 are: Ti-46 (8.0%), Ti-47 (7.5%), Ti-49 (5.5%), and Ti-50 (5.5%).
Calculate the percent abundance of the isotope titanium-48.
Using the percent abundances given in the context and your answer to part A(i), calculate the average atomic mass of this sample of titanium. Express your answer to the nearest 0.01 amu.
The photoelectron spectrum (PES) for a neutral atom of titanium is shown in Figure 2.
Figure 2. Photoelectron spectrum (PES) for titanium (binding energy on a logarithmic axis increasing to the left)
Based on the electron configuration of titanium, identify the subshell corresponding to the peak at the highest binding energy in Figure 2.
Explain why the binding energy of the electrons in the 1s subshell of titanium is greater than the binding energy of the electrons in the 1s subshell of scandium (Sc).
The atomic radius of titanium is 140 pm, while the atomic radius of calcium (Ca) is 197 pm. Explain this difference in terms of atomic structure.
A student conducts an experiment to determine the empirical formula of a titanium chloride compound. The student reacts 1.25 g of pure titanium metal with excess chlorine gas, Cl₂(g), using the apparatus shown in Figure 3. After the reaction is complete, the mass of the product is found to be 4.95 g.
Figure 3. Reaction apparatus for forming a titanium chloride using flowing chlorine gas and heating titanium metal
Using the data provided in the experiment description and Figure 3, calculate the empirical formula of the titanium chloride compound formed.
Ti(s) + 2Cl₂(g) → TiCl₄(l)
The reaction between titanium and chlorine is represented by the equation below.
Write the complete ground-state electron configuration for the Ti⁴⁺ ion.
Explain why the second ionization energy of titanium is greater than the first ionization energy.
In a separate trial, the student does not heat the titanium long enough, leaving some unreacted titanium metal mixed with the product. How would this error affect the calculated ratio of moles of Cl to moles of Ti in the compound? Justify your answer.
00:00
