Question

1. a chemical change is shown in the picture below. name three signs that you could use to tell that it is a chemical change.
2. look at the picture below. which of the two glasses, a or b, contains a dissolved mixture? describe the difference between the particles in the dissolved mixture and the contents from the other glass.

Explanation:

1. For the first question about the signs of a chemical - change in the rusting of a car: A chemical change occurs when new substances are formed. Rust is a new substance (iron oxide) formed from iron, oxygen, and water. A color change is visible as iron (usually silver - gray) turns to a reddish - brown rust. Also, heat or light can be released or absorbed in a chemical change (although not as obvious in rusting at first glance). Another sign is the formation of a new substance with different properties than the original.
2. For the second question, glass (a) is in the process of forming a dissolved mixture as sugar is being added to water. In a dissolved mixture (solution), the solute (sugar) particles are evenly distributed at a molecular level among the solvent (water) particles. In glass (b), which is a saturated sugar solution, the maximum amount of sugar has been dissolved at that temperature. If more sugar is added, it will not dissolve and will settle at the bottom. The main difference between the two is that in glass (a), more sugar can still be dissolved, while in glass (b), the solution is at its saturation point and cannot dissolve additional sugar under the current conditions.

Answer:

1. Three signs of a chemical change in the rusting of the car: Color change, formation of a new substance (rust), and potential heat/light change (less obvious in rusting).
2. Glass (a) contains a dissolved mixture as sugar is being added. In the dissolved mixture (glass a), sugar particles are being dispersed molecularly in water. In glass (b) (saturated solution), the solution has reached its capacity to dissolve sugar and any additional sugar will not dissolve and may settle.