Question

Which grouping identifies chemical properties?A. Density, luster, boiling point B. Melting point, hardness, conductivity C. Malleability, ductility, texture D. Combustibility, flammability, reactivity

Answer 1

Answer:

• option D. Combustibility, flammability, reactivity.

Explanation:

• Physical properties: characteristics of the matter that can be observed and measured by physical media, withoud changing the composition of the matter.

 

        Typical examples of physical properties are: mass, volume, density, boiling point, melting point, hardness, specific heat.

• Chemical properties: they are ability of the matter to change by decompositon or combination with other substances to produce one or more different substances. They cannot not be observed or measured without changing the composition of the orignal sample.

        Typical examples of chemical properties are reactivity with oxygen, reactivity with water, and any reactitivy in general.

Hence, applying those definitions to the set of choices you get:

A. Density, luster, boiling point (incorrect)

All of them are physical properties since they are observable and measurable without altering the composition of the sample.

B. Melting point, hardness, conductivity (incorrect)

They all are also physical properties. For example, melting point can be measured with a thermometer during the phase change.

C. Malleability, ductility, texture (incorrect)

Again, all physical properties. Ducitlity, for example, is the ability of the metals to form this wires.

D. Combustibility, flammability, reactivity (correct answer)

• Combustibility: is the reaction with oxigen to form CO₂ and H₂O

• Flammability: is the ability to burn in flames, which is a chemical change.

• Reactivity: Already discussed.

       All these properties can only be measured by producing the correspondant chemical reaction (change), so they are chemical properties.