Question

how many g of agno3 would you need to make a 575ml solution of 0.25 m agno3

Answer 1

If you expect to get along in chemistry you should find the caps key and use it. There is a difference between 0.25m and 0.25M. I suspect you mean 0.25M.
How many mols do you need? That's M x L = ?
Then mols = grams/molar mass. You know molar mass and mols, solve for grams.