How much weight can the studs in a non load bearing wall support?
Non-load bearing means that it doesn't have the weight of the roof and ceiling bearing on it, basically, it can be removed with no ill effects. This has no bearing whatsoever on its capacity to hold a load, which has more to do with how the wall is tied in with the floor and roof joists. If you had a modern home I wouldn't worry about it. Since your home is (probably) not up to modern building codes you could have a professional mount it and thus bear any liability for the failure of the wall. If that isn't an option, inspect the condition and spacing of your studs and the anchoring of the wall into the floor and ceiling.