Scientific Tutor

How are states of matter displayed in a chemical equation?

In this section we are going to show you how states of matter are displayed in a chemical equation. The states of matter are gas, like the air we breath, liquid, like the water we drink, solid, like the ground we are standing on, and aqueous like the sugary drink we taste.

The notation for each state is as follows below:

Gas = (g)

Liquid = (l)

Solid = (s)

Aqueous = (aq)

All the state of matter notations go at the end of each chemical next to the subscript.

Examples:

H₂SO_4(aq) —> H_2(aq) + S_(s) + O_2(aq)

H_2(g) + O_2(g) —-> H₂O_(l)

In the first equation, H₂SO₄ is in an aqueous state. In the second equation, H₂O is in a liquid state.

Use the practice problems below to bring together your understanding of reactants versus products and the different states of matter.

PRACTICE PROBLEMS: Give the states of matter for the requested chemicals below.

What are the states of matter for the products of the chemical equation below?

Ag_(s) + Ca₃(PO₄)_2(s) —-> Ca_(aq) + Ag₃PO_4(s)

Answer: Ca = aqueous, Ag₃PO₄ = solid

What are the states of matter for the reactants of the chemical equation below?

C₄H_{10 (l)} + O_{2 (g)} —-> CO_{2 (g)} + H₂O_(g)

Answer: C₄H₁₀ = liquid, O₂ = gas

What are the states of matter for the products of the chemical equation below?

Ba(OH)_2(aq) + HCl_(aq) —-> H₂O_(l) + BaCl_2(aq)

Answer: H₂O = liquid, BaCl₂ = aqueous

What are the states of matter for the reactants of the chemical equation below?

C_4(s) + O_2(g) —> CO_2(g)

Answer: C₄ = solid, O₂ = gas