How many molecules are in 1.35 moles of lactic acid (C6H6O)

= 8.13 x 10²³ molecules of lactic acid per mole

Explanation:

Molecules of Lactic Acid in 1 mole:

One mole ( 1 mole) of any substance whether element or compound contains 6.02 x 10²³ particles of that substance.

That is => 1 mole substance = 6.02 x 10²³ particles of that substance

∴ 1.35 moles lactic acid = 1.35 moles x 6.02 x 10²³ particles lactic acid /mole

= 8.13 x 10²³ molecules of lactic acid per mole.

Note (for what it's worth) ... Number of Atoms ...

Given the formula of lactic acid C₆H₆O represents 1 mole of the compound, the subscripts represent moles of each element in the compound. That is, there are 6 moles carbon, 6 moles hydrogen and 1 mole oxygen atoms in each mole of lactic acid. So, if one were to ask, How many atoms of carbon are there in 1 mole of lactic acid? =>  then ...

1 mole C₆H₆O => 6 moles H = 6 moles H x 6.02 x 10²³ atoms/mole = 3.612 x 10²⁴ atoms of hydrogen in 1 mole of lactic acid. Same logic will give atoms of Hydrogen and Oxygen if needed.

4d^55s^1 ( third choice)