Question

Label each of the following as either a physical process or a chemical process: (a) corrosion of aluminum metal, (b) melting of ice, (c) pulverizing an aspirin, (d) digesting a candy bar, (e) explosion of nitroglycerin.

Short answer

(a) Corrosion of aluminum metal: Chemical process (b) Melting of ice: Physical process (c) Pulverizing an aspirin: Physical process (d) Digesting a candy bar: Chemical process (e) Explosion of nitroglycerin: Chemical process

Step-by-step solution

(a) Corrosion of aluminum metal

Corrosion is the process of gradual destruction of metal due to a chemical reaction with its surrounding environment, such as air or water. In the case of aluminum metal, the corrosion leads to the formation of aluminum oxide. Since the molecular composition changes, this is a chemical process.

(b) Melting of ice

Melting of ice involves the change of state from solid (ice) to liquid (water) without altering its molecular composition. Both ice and water are composed of H2O molecules, and therefore, it is a physical process.

(c) Pulverizing an aspirin

Pulverizing an aspirin tablet involves breaking it down into smaller pieces or powder without altering its molecular structure or composition. This process only changes the physical appearance of the aspirin tablet; hence, it is a physical process.

(d) Digesting a candy bar

Digesting a candy bar involves the breakdown of the complex substances present in the candy bar into simpler molecules that can be absorbed and used by the body. This process changes the molecular composition of the substances in the candy bar, so it is a chemical process.

(e) Explosion of nitroglycerin

An explosion of nitroglycerin is a chemical reaction in which nitroglycerin rapidly decomposes to produce various gaseous products and releases a large amount of energy in the form of heat, light, and sound. Since the molecular composition of nitroglycerin changes during the explosion, it is a chemical process.