Question

Which of the following equations shows a chemical change?(1 point)
Responses

C3H8+5O2→3CO2+4H2O

C2H5OH(l)→C2H5OH(g)
C 2 H 5 O H, which is a liquid right-arrow C 2 H 5 O H, which is a gas

NH3(g)→NH3(l)
N H 3, which is a gas right-arrow N H 3, which is a liquid

H2O(s)→H2O(g)

Answer 1

The equation that shows a chemical change is:

**C3H8 + 5O2 → 3CO2 + 4H2O**

This equation represents the combustion of propane (C3H8) in the presence of oxygen (O2), resulting in the formation of carbon dioxide (CO2) and water (H2O). This involves breaking and forming bonds, which is characteristic of a chemical change.

The other equations represent physical changes (phase changes) where the chemical identity of the substances remains the same:

- C2H5OH(l) → C2H5OH(g) (liquid to gas)
- NH3(g) → NH3(l) (gas to liquid)
- H2O(s) → H2O(g) (solid to gas)