We just replaced a double sink with a single sink. We want to reuse our fairly new garbage disposal in the new sink. If the disposal is set up for the double sink can I use it in the single sink? THanks for your help!

Sure can. Run a straight piece of pipe from the disposal output into a P trap and then into the wall connection. Best to hook up the dishwasher through the disposal using a high loop air gap. Make sure to knock out the DW connector if you are not using the DW this way now.