Practicing Success
Which of the following is not a pure substance? |
Copper Gold Sugar solution Water |
Sugar solution |
The correct answer is option 3. Sugar solution. A pure substance is a material that has a constant composition and distinct properties. Let's examine each option to understand why a sugar solution is considered not a pure substance: 1. Copper: Copper is an element, and if it is in a pure form without any impurities, it is a pure substance. It consists of only one type of atom (Cu). Similar to copper, gold is an element. In its pure form without impurities, it is a pure substance. It consists of only one type of atom (Au). A sugar solution is a mixture composed of sugar (a compound) dissolved in water (a compound). Since it is a mixture of different substances and does not have a constant composition throughout, it is considered not a pure substance. The properties of a sugar solution can vary depending on the ratio of sugar to water. Water, in its pure form (without impurities), is a compound and, therefore, a pure substance. It consists of two hydrogen atoms and one oxygen atom (H₂O). In summary, while copper, gold, and pure water are examples of pure substances, a sugar solution is a mixture and not considered a pure substance due to its variable composition. The properties of a sugar solution can change depending on the amount of sugar dissolved in water. |