Chalk powder does not dissolve completely in water; instead, it forms a suspension, where the chalk particles remain dispersed but visibly settle over time.
Here's a more detailed explanation:
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Insoluble Nature: Chalk is primarily composed of calcium carbonate (CaCO3), which is largely insoluble in water. This means the calcium carbonate molecules don't readily break apart and mix evenly with water molecules at a molecular level.
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Suspension Formation: When chalk powder is mixed with water, the chalk particles become dispersed throughout the liquid. However, these particles are large enough to be seen with the naked eye. Because they are not dissolved, they will eventually settle out of the solution due to gravity. This type of mixture is called a suspension.
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Distinguishing from Solutions: A true solution, like salt dissolved in water, involves the solute (salt) completely dissolving and becoming uniformly distributed throughout the solvent (water). In a solution, you cannot see the solute particles. With chalk powder in water, the chalk particles remain visible.
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Settling: Over time, the force of gravity will pull the chalk particles down, and they will accumulate at the bottom of the container. This settling is a characteristic feature of suspensions.
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Example: If you stir chalk powder into water, the water will initially appear cloudy. If you let the mixture sit undisturbed for a while, you'll see the chalk settle to the bottom, leaving clearer water on top.
In summary, chalk powder in water forms a suspension because the chalk particles do not dissolve but rather remain dispersed and eventually settle out.
