From the purchase of a condo, the purchaser becomes responsible for the unpaid common expenses of the vendor (Article 1069 C.C.Q.). The syndicate may, therefore, claim from you amounts that you would not have thought owing.
On the other hand, if the notary, the real estate broker or you have asked the syndicate for a statement of common expenses before the signing of the deed of sale, and the syndicate has not supplied it in a delay of 15 days from the request, the latter will not be entitled to claim such unpaid common expenses from you.
WARNING! The liability of the notary could be invoked in relation with unpaid common expenses of the vendor. Indeed, a notary is at fault towards a purchaser if he fails to request a statement of the common expenses owing.