In which of the following pairs are both chemical properties?
A) has metallic luster, soluble in ammonia
B) flammable, reacts with acid
C) green in color, reacts violently with water
D) has a high density, is very brittle
The correct answer and explanation is :
The correct answer is B) flammable, reacts with acid.
Explanation:
Chemical properties describe how a substance interacts with other substances and involves the formation of new substances. These properties are indicative of the substance’s ability to undergo a chemical change. Let’s analyze each pair:
- A) has metallic luster, soluble in ammonia:
Metallic luster is a physical property, as it refers to how a material reflects light. It does not involve a change in the chemical composition of the substance. Soluble in ammonia refers to the ability of a substance to dissolve in ammonia, which is also a physical property. Therefore, this pair contains only physical properties, not chemical ones. - B) flammable, reacts with acid:
Flammability is a chemical property because it describes how a substance reacts with oxygen in the presence of heat to undergo combustion. It involves the chemical transformation of the substance into new products (like carbon dioxide and water). Similarly, reacting with acid is another chemical property, as it describes a substance’s ability to undergo a chemical reaction with an acid, often resulting in the release of gases, formation of salts, or other products. Since both flammability and reactivity with acids involve chemical changes, this pair contains two chemical properties. - C) green in color, reacts violently with water:
Green in color is a physical property, as color is a characteristic that does not involve a chemical change. Reacting violently with water, on the other hand, is a chemical property, as it involves a substance chemically reacting with water. Since one property is physical and the other is chemical, this pair does not contain both chemical properties. - D) has a high density, is very brittle:
High density and brittleness are both physical properties. Density refers to the mass per unit volume of a substance, and brittleness refers to how a material breaks when subjected to stress. Neither involves a chemical transformation, so this pair only includes physical properties.
Thus, option B is the correct choice because both flammability and reactivity with acid are chemical properties.