A321 First Officer reported a fume event during descent; which was also experienced by the flight attendants. Flight landed safely and a logbook entry was submitted.

Narrative

Upon arrival into ZZZZ; around 8;000 ft. I detected a subtle chemical odor which I could not immediately determine the cause. It was faint; and was not an odor I had experienced before; not like the old dirty sock smell. I didn't mention what I had noticed to the Captain since it was so subtle and I was still trying to personally classify the odor. Shortly later a call from the flight attendants came up and I knew immediately they were calling about that odor. They had mentioned a strong smell in the aft cabin; rows 27 forward to 12; which resembled a magic marker; vinegar; chemical smell. They said it was strong and that passengers could smell it as well. We were around 6;000 ft. when we were notified. We referenced the FCOM (Flight Crew Operations Manual) Odor Recognition and Isolation guide; but due to the short duration of the remainder of the flight we did not have the appropriate time to isolate systems and wait to see if the odor would dissipate or not. The Captain called back a short while later to see if there had been any improvements to the odor. The response was that it was still present but had dissipated and now had a sweet smell. The flight landed and arrived at the gate without incident. Upon landing we contacted the flight attendants to get a summary of what they experienced to make an accurate logbook entry. The FA (Flight Attendant) 3 had noticed the odor the most and was the first to make the call; so we queried him. His summary was as stated before; that he had noticed the strong magic marker; vinegar; chemical smell around the 10;000 ft. chime; and it continued upon descent. He called us shortly after experiencing the smell and had asked other customers and flight attendants if they smelled anything; which they agreed. It dissipated slightly; but remained for the rest of the flight. He stated that the strong chemical smell dissipated into a sweet smell; but he complained of a slight throat irritation. A logbook entry was made; an odor report filled out; and Maintenance was contacted.