Question

How many molecules of glucose are in 2.0 ml of a 1.02 mM solution of glucose?

Answer 1

Volume in liters:

2.0 mL / 1000 => 0.002 L

Molarity = 1.02 M

Number of moles glucose :  

n = M  x V

n = 1.02 x 0.002 => 0.00204 moles

1 mole ------------------ 6.02x10²³ molecules
0.00204 moles ------ ??

0.00204 x ( 6.02x10²³) / 1 =>  1.228x10²¹ molecules of glucose

hope this helps!