Which of the following terms are unitless?

Molality is measured as and the unit is molal or moles per kg.

Molarity is measured as and the unit is Molar or moles per liter.

Mole fraction is calculated as and it does not have units as it is a fraction.

Mass Percent is calculated as and it is unitless as it is a ratio multiplied by 100.

The correct answers are (iii) and (iv).