Scientific Tutor

How does molar mass affect the state of matter?

The molar mass of an element or compound has a lot to do with determining its possible state of matter (solid, liquid, gas) generally as the molar mass of a substance increases then it gets more and more dense. As the density increases it is more likely to be in the solid state. Therefore;

As the molar mass of a chemical INCREASES it is more likely to be the MOST dense state possible (usually SOLID).

As the molar mass of a chemical DECREASES it is more likely to be the LEAST dense state possible (usually GAS).

Examples: Answer the questions below. Molar mass versus states of matter examples below.

From the compounds below which one is most likely to be a solid?

NaCl, LiF, RbI, KBr

Answer: RbI

Out of the molecules below which one is most likely to be a gas?

F₂, Cl₂, Br₂, I₂

Answer: F₂

PRACTICE PROBLEMS: Answer the questions below.

From the compounds below which one is most likely to be a gas?

H₂S, H₂O, H₂Se, H₂Te

Answer: H₂O

Out of the molecules below which one is most likely to be a Solid?

Ar, Xe, Ne, He

Answer: Xe

If you have a 4 separate containers of each chemical below and 3 of them are solids and one is a liquid, which one is most likely to be the liquid?

CsI, RbBr, LiF, KCl

Answer: LiF

Which chemical below will become a gas first?

NH₃, PF₃, AsBr₃, PI₃

Answer: NH₃