Classify each of the following as a pure substance or a mixture. If a mixture, indicate whether it is homogeneous or heterogeneous. Drag the appropriate items to their respective bins. baking soda tap water sawdust cola with ice Pure substance Homogeneous mixture Heterogeneous mixture
The Correct Answer and Explanation is:
Here’s the classification of the substances:
- Baking Soda: Pure substance
Baking soda is a pure substance because it is a single chemical compound with a consistent composition. It is chemically known as sodium bicarbonate (NaHCO₃), and no matter how much of it you have, its composition remains the same throughout. - Tap Water: Homogeneous mixture
Tap water is a homogeneous mixture. It is primarily composed of water (H₂O), but it contains various dissolved substances like salts, minerals, and sometimes chemicals added for purification (like chlorine or fluoride). Since these dissolved substances are evenly distributed throughout the water, it is a homogeneous mixture. - Sawdust: Heterogeneous mixture
Sawdust is a heterogeneous mixture because it consists of small, solid particles of wood that do not form a uniform composition. The size and shape of the sawdust particles can vary, and if you observe it closely, you can easily identify distinct components (wood fibers, possibly dust, etc.), making it a heterogeneous mixture. - Cola with Ice: Heterogeneous mixture
Cola with ice is also a heterogeneous mixture. Although the cola itself is homogeneous, the presence of ice introduces a phase change (solid ice and liquid cola). The ice is not dissolved in the liquid, and as the ice melts, the composition of the mixture changes in different parts of the drink. Hence, the mixture is heterogeneous.
Explanation:
- Pure substances are materials that have a consistent and uniform composition throughout. They are made up of only one type of molecule or atom, like water (H₂O) or baking soda (NaHCO₃).
