A chemical problem may be presented to you in units of moles, mass, or volume. Which one of these can be directly used in your arithmetic no matter what the conditions are?
moles.
The unit of moles can be directly used in arithmetic no matter what the conditions are. In chemistry, moles are a fundamental unit of measurement that express the amount of a substance. One mole is equal to the number of atoms in 12 grams of carbon-12, which is approximately 6.022 x 10^23 entities (Avogadro's number).
Moles are independent of temperature, pressure, or any other conditions, which makes them suitable for calculations in various scenarios. When using moles in arithmetic, you can perform calculations such as molar mass, stoichiometry, and concentration without having to consider the specific conditions like temperature and pressure.