I have Hunts 100% natural no salt added tomato sauce. There is only one variety that Huntz makes that says "Tomato Sauce".
I am wondering how much baking soda will be enough to neutralize the acid. The can is exactly 8 ounces.
It is not possible to solve this analytically and give an answer, because tomato sauce is not a simple solution of a single acid in water, but more complex - and besides, producers tend to keep the exact amounts of ingredients a trade secret.
If you want to neutralize the acid, you will have to use a pH meter of some kind (the paper strips will not be a good choice though, because the tomato will likely color them) and titrate.