is this a chemical or physical change
1. a glowing splint placed in a test tube causes a loud pop
2. food coloring is added to cake icing to make it pink
1. Something must have reacted with the glowing splint to make the pop; therefore, that must be a chemical change.
2. This probably is a physical change. Probably there is no reaction. (I say probably because a change in color does, at times, denote a chemical change. For example, iron(III) ion plus thiocyanate ion produces a blood red color due to the formation of the iron thiocyanate complex ion.)
1. Ah, the old "pop goes the splint" experiment! Well, this is actually a chemical change. The loud pop indicates that a combustion reaction has occurred. It's like splint fireworks! Just be careful not to start a circus in the lab.
2. Ah, the quest for that perfect pink icing! This one is a physical change. When you add food coloring to the icing, it simply mixes with the existing icing molecules, causing a change in color. It's like giving the icing a trendy new outfit without altering its actual composition. Fashion-forward frosting, I must say!
1. The reaction between a glowing splint and the contents of a test tube (presumably a flammable gas) causing a loud pop is a chemical change. This is because a new substance is formed, indicated by the change in color, formation of a gas, and the release of sound.
2. Adding food coloring to cake icing to make it pink is a physical change. This is because the food coloring does not react chemically with the icing, rather it mixes uniformly to change the appearance of the icing without altering its chemical composition.
To determine whether each scenario represents a chemical or physical change, let's first understand the difference between the two.
A physical change is a transformation that does not alter the chemical composition of a substance. In other words, the substance remains the same at a molecular level; only its physical properties, such as shape, size, or state, may change.
On the other hand, a chemical change involves a transformation at a molecular level, resulting in the formation of new substances with different chemical properties.
Now, let's analyze each scenario:
1. When a glowing splint placed in a test tube causes a loud pop, it represents a chemical change. This reaction is typically referred to as the "pop test" and is used to detect the presence of hydrogen gas (H2). In this case, the oxygen (O2) in the air reacts with hydrogen gas inside the test tube, resulting in a chemical reaction that produces water (H2O).
2. Adding food coloring to cake icing to make it pink is a physical change. Food coloring is a dye that only affects the visual appearance of the icing without altering its chemical composition. The cake icing remains the same substance; only its appearance changes from colorless to pink due to the dispersion and absorption of certain wavelengths of light by the food coloring molecules.
To summarize, the first scenario represents a chemical change, and the second scenario represents a physical change.