what is chloride percentage in this salt.the label says sodium only.

The label does not mention chloride on the label. That’s all I know. It has no clumping agent per the label either. All I can tell u is it is really good sea salt!

Does this container have 12 or 16 ounces of salt?

12 oz The label says .75 lbs (340.2g)

Would this be good on a beef rib roast for bringing

Jacobson pure kosher salt is the best salt, been using this salt for 4 years, won’t use any other salt. If your beef recipe calls for kosher salt then yes this salt would be great to use to brine your meat, and good to brine a turkey, it is expensive.

Can this be used in a salt grinder or will it gum it up?

Hi, thank you for your inquiry. The Jacobsen Kosher Sea Salt shouldn't gum up a grinder. The Kosher Sea Salt is a very fine flake - likened to a traditional table salt. Much of the salt would just fall through the openings of a grinder with good shake. We suggest manually sprinkling this salt or using a measuring spoon when baking or when measuring is otherwise called for.