Question

In our lab, we performed a wittig reaction with benzyltriphenylphosphornium chloride and benzaldehyde with NaOH as our base. And washed the reaction with dicholoromethane, sodium bisulfite, and water. It was dried with sodium sulfate. *Side note: there was a lot of dicholormethane added in excess due to the mixture soldifying and needed to be dissolved and when the final organic layer (washed and dried) was put on a hot plate it exploded at a very low heat.** My yield came out 166% which obviously is not correct and it is contaminated. What are some issues that would create this issue with yield and what measures or precatutions can help in the future? Also, could dicholoromethane be the reason the product exploded? Thanks!