Within 20 % error - yes.
Within 5 % error - no.
I'm not concerned about the error 5 or 20% but the osmolarity of sodium ascorbate in grams in the final solution.
Care to share the formula how I could measure that, and how you come up with 5-20% errors?
PS: An acquaintance has tried with 100 grams in 1000 ml, with normal osmolarity of 300 mosm/l....but is away, otherwise won't have bothered you.