The reaction mixture should be refluxed for 45 minutes. This means that the distillation should be started 45 minutes after the flask with the reaction mixture is placed on the sand bath the mixture begins to boil. the reagents are combined in the flask the start of lab QUESTION 4 Which part of the apparatus (refer to the diagram in the textbook) should be wrapped with a damp pipe cleaner while refluxing? The upper part of the long-neck flask and the part of the Claisen head that is below the aircondenser sidearm. The lower part of the neck of the flask. The air condenser that forms the sidearm of the Claisen head. The round part of the flask just above where it is immersed in the sand