1. (30 pts) Consider the hypothetical compound solid AlCl. Estimate the lattice energy using the Born-Mayer equation. To find the cationic radius examine the per cent reduction of the radius for several metals from the neutral to the +1 state and use this as a guide to estimate the cationic radius. Assume the NaCl lattice and that d* = 34.5 pm. Use your estimate to calculate the standard heat of formation for AlCl. Does your calculated heat of formation account for the nonexistence of AlCl solid? Why or why not? Cite the source for any data you need to look up.
2. (10 pts) MoS2 is currently a heavily studied material because it can act as a semiconductor. Explain why this compound is semiconducting?
3. (10 pts) Consider H2CrO4 and HMnO4. Write the Brønsted-Lowry reaction of each of these acids with water. Which of these is the stronger acid? Explain your reasoning.