How to find density - pls be simple

How many moles are in 7.2 x 10^23 carbon molecules? (*round to the nearest hundredth and include the unit "mol c" after your number) question 6 options:

Gusing the milligrams of ascorbic acid you entered above, the ratio of total sample volume to aliquot volume, and the total milligrams of the vitamin c tablet that you dissolved, calculate the mass of ascorbic acid in the vitamin c tablet for each trial. do this by scaling up to find the amount (mg) of ascorbic acid in your 250 ml flask. enter your calculated mass of ascorbic acid in the vitamin c tablet, for each trial. be sure to enter your calculated mass in the corresponding order that you entered your milligrams of ascorbic acid. the milligrams of ascorbic acid you entered for entry #1 previously should correspond to the mass of ascorbic acid that you enter for entry #1 here.

Aliquid solution can be made select all that apply. dissolving solids into liquids, mixing liquids, dissolving gas solutes into liquids , mixing gases, mixing solids