Question

question #12
sodium chloride

1. white to colorless crystals
2. reacts with silver nitrate to form a solid
3. density = 2.47 g/cm³
4. dissolves in water

a student studying sodium chloride (nacl) makes a list of its properties. which observations are physical properties?
a observations 1, 3, and 4 only
b observations 2, 3, and 4 only
c observations 1 and 2 only
d observations 2 and 4 only

Explanation:

Physical properties describe a substance without changing its chemical identity. Color (white to colorless crystals), density ($2.47\ \text{g/cm}^3$), and solubility in water are physical properties. Reaction with silver nitrate forms a new substance (silver chloride), so it is a chemical property. Thus, observations 1, 3, and 4 are physical properties.

Answer:

A. Observations 1, 3, and 4 only