An unknown element X has the ground-state electron configuration
[Ar]3d104s24p1.
A student bubbles chlorine gas through an aqueous solution containing X–ions and isolates a solid product whose molar mass is 239gmol−1. Assume chlorine is present as Cl− in the product.
(a) Identify the period and group in which element X is located.
(b) Determine the number of valence electrons for X and predict the most probable ionic charge it adopts in aqueous solution.
(c) Using your predicted ionic charge, write the empirical formula of the chloride isolated by the student and calculate its theoretical molar mass. Compare this value with the experimental molar mass and comment on any consistency or discrepancy.
(d) Predict the formula of the compound formed when X reacts with the polyatomic ion sulfate, SO42−, and justify your answer.