Looks like a Linden, Tilia is the genus name.

Tilia henryana (Henry's Lime), readily identifiable by the soft-spine like teeth on the leaf margins. A rare Chinese species, very desirable.
{{gwi:376334}}

Resin

I don't think it's Tilia henryana. Typically the "spines" of the soft spine like teeth are much longer on T. henryana than the leaves in the photo. You can find T. americana(Basswood, American Linden) with leaves with small soft "spine" like teeth like the leaves in the photo. The leaves look too large for T. henryana, which top out at about 4"x4"(10cm x 10cm), to me also. They look much closer in size to T. americana, which range from 4"x4" on the small side up to 8"x8"(20cm x 20cm), to me. Also, T. henryana in cultivation has so far been a relatively small tree in the 30' to 35' range(roughly 10m). Lastly, I'm doubtful that T. henryana(considered zone 7 hardy usually) is hardy in the zone 5 Brookfield Zoo which has seen temps as low as -20°F(-29°C) within the past 12 years or so(surely within the lifetime of this tree). So, I believe this is a Basswood tree(T. americana).

{{gwi:376326}}

I forgot to add that T. henryana flowers in August to September, while T. americana flowers in May to July(depending on local climate) which would eliminate T. henryana from being a possibility for the tree in the photo.

Is T. henryana hardy in zone 5? Are the flowers fragrant as well?

Every Tilia I've come across so far is fragrant when in flower(some more than others) and so is T. henryana. It's not listed as being hardier than zone 7 in most references, but I've seen a few reports of it possibly being hardier(some arboretum and botanic gardens in zone 6 growing it), so I'd give it a shot if you can find one to purchase.