what mass of AgNO3(MW 169.87) is required to make 25 mL of 0.100 M AgNO3?

Answer 1

0.100 mole/liter * 0.025 liters = 0.0025 moles

Multiply that by 169.87 g/mol for the number of grams of AgNO3 required.

Only two or three significant figures should be in the answer, because the input numbers (like 25 ml) were not very precise.