Which statement explains why NaBr is classified as a compound?
1.Na and Br are chemically combined in a fixed proportion.
2.Na and Br are both nonmetals.
3NaBr is a solid
298 Kand standard pressure.
4.NaBr dissolves in H20 at 298 K.
The Correct Answer and Explanation is :
The correct statement that explains why NaBr is classified as a compound is:
1. Na and Br are chemically combined in a fixed proportion.
Explanation
A compound is defined as a substance formed when two or more different elements chemically bond together in fixed ratios. In the case of sodium bromide (NaBr), sodium (Na) and bromine (Br) combine in a 1:1 ratio. Sodium is a metal, while bromine is a nonmetal; when they react, sodium donates one electron to bromine, resulting in the formation of ionic bonds. This specific ratio (one sodium atom for one bromine atom) is crucial because it illustrates that the compound has a consistent composition regardless of the amount taken or produced.
Let’s briefly analyze the other statements:
- 2. Na and Br are both nonmetals. This statement is incorrect because sodium is a metal, while bromine is a nonmetal. A compound can form between a metal and a nonmetal, and NaBr is a prime example of such an ionic compound.
- 3. NaBr is a solid at 298 K and standard pressure. While it’s true that NaBr is a solid under these conditions, the state of matter does not determine whether a substance is classified as a compound. Many elements can exist as solids, liquids, or gases, but this alone does not indicate their chemical nature.
- 4. NaBr dissolves in H₂O at 298 K. Although NaBr is soluble in water, solubility is a physical property that does not define the chemical identity of a compound. Compounds can exhibit various solubility behaviors, and while solubility is an important characteristic, it does not justify the classification of a substance as a compound.
In summary, the defining characteristic of NaBr being a compound is the chemical combination of sodium and bromine in a fixed ratio, forming a stable ionic compound.