Explain the mechanism of Friedel-Crafts Acylation of creating a ketone from a Benzene ring and Acetyl Chloride using Aluminum Chloride as the catalyst.
Because of high electronegativity on the Chloride atoms attached to the catalyst, the Aluminum is given a partial positive charge. The result is the Chloride atom attached to the Acetyl Chloride is given to the catalyst giving the catalyst an overall negative charge. The Acetyl Chloride is now just an Acetyl group with a positive charge that is highly reactive. The benzene molecule is able to take on the positive Acetyl molecule, breaking one of its double bonds and giving the carbon next to the now bonded acetyl group a positive charge. The catalyst is then able to give the extra Chloride atom to the hydrogen on the carbon-acetyl bond, and the double bond on the benzene ring can be reformed by electron transfer. the products of this reaction are Acetyl Benzene, the Aluminum Chloride catalyst, and Hydrogen Chloride.
Using what you know about acid-base chemistry, explain how antacids work to help with indigestion and upset stomach?
Because indigestion and upset stomach are usually caused by an unnatural fluctuation in stomach pH, antacids are buffers designed to counteract the effects of eating overly acidic or basic foods. Buffers are typically weak acids and bases and neutralize the strong acids and bases that typically cause upset stomach and indigestion. This can help to minimize the change in stomach pH.
When going from left to right across the periodic table, does the radius of an atom increase or decrease and why?
The general trend going from left to right across the periodic table is a decrease in radius of the atom. This is due to the increasing size of the nucleus and the resulting pull on the surrounding electrons.