Final answer:
To make 500 mL of hot chocolate, you would need 5 scoops of powder and 500 mL of milk according to the 1 scoop per 100 mL ratio.
Step-by-step explanation:
The ratio of powder to milk for most hot chocolate is 1 scoop to 100 ml. To make 500 mL of hot chocolate, you would need 5 times the amount of each ingredient since 500 mL is 5 times larger than the single serving of 100 mL.
Therefore, you would need 5 scoops of powder and 500 mL of milk.