Final Answer: The disappearance of the powder is most likely the result of the powder 1 dissolving in the warm water, which is an example of a 2 physical change of matter. So, a chemical reaction 3 did not occur.
Explanation:
The observations suggest that a chemical reaction occurred between the powder and the water. When the powder was mixed into the water, it gradually disappeared, indicating that it dissolved in the warm water. This is an example of a physical change of matter, where the powder changed state and became dispersed throughout the water. However, as the water cooled down, the powder collected again at the bottom of the beaker. This suggests that a chemical reaction took place between the dissolved powder and the water molecules. The cooling of the water likely caused the reactants to come together and form a solid precipitate, which settled at the bottom of the beaker. This phenomenon can be explained by the concept of solubility. When a substance dissolves in a solvent, such as water, it forms a homogeneous mixture. However, if the conditions change, such as temperature or concentration, the solubility of the substance may be affected. In this case, as the water cooled down, the solubility of the powder decreased, causing it to come out of solution and collect as a solid. Therefore, based on these observations, it is likely that a chemical reaction occurred between the powder and the water, leading to the formation of a precipitate as the water cooled. A beaker of water is heated to 50°C. Then an unidentified powder is mixed into the water. The powder gradually disappears. However, as the water cools, the powder collects again at the bottom of the beaker.
Do the observations show that a chemical reaction occurred between the powder and the water?
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The disappearance of the powder is most likely the result of the powder 1 dissolving in the warm water, which is an example of a 2 physical change of matter. So, a chemical reaction 3 did not occur.