Question

(X) A mysterious clear, pink liquid is found in a laboratory. Upon being heated, most of the liquid evaporates as colorless vapor, leaving behind a red solid. Based on these observations, the original pink liquid was most likely (a) an element (b) a compound (c) a homogeneous mixture (d) a heterogeneous mixture (xi) Would you classify the evaporation that happened in (xii) as a physical change or as a chemical change?

Answer 1

x. The liquid must have been a homogeneous solution of water and some red solid. That is why it was clear. When it was heated, the water evaporated leaving the solid behind. The pink colour of the liquid was due to the low concentration of the red solid.

So, it was a solution. Solution is a homogeneous mixture.

So, the answer is, c) a homogeneous mixture.

xi. In the process above, no chemical reaction took place. It was a physical method of separating two components of a mixture. So, it is a physical change.

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