59.17 oz1 liter = 33.814 oz 1 oz = 0.02 L
3.5 US fluid ounces = 0.103507353 litres
16.9070113 1 litre = 33.8140226 US fluid ounces, so .5 liter = 16.9070113 US fluid ounces.
There are 33.8140227 fluid ounces in a liter.
A litre is a unit of capacity. An ounce is a unit of mass. Without some unit of density to compare, the two units are incompatible.