How much is 5oz fluid in grams?

Surely that depends on the mass of the fluid you're using. 5 fluid ounces of ether would weigh less than 5 fluid ounces of water because ether is less dense than water and therefore lighter.

If you want a straight conversion from Ounces (Not fluid ounces) to grammes then this question has already been answered at ;

How_many_metric_grams_is_5oz