A chemist wants to extract copper metal from copper chloride solution. The chemist places 0.25 grams of aluminum foil in a solution of 0.40 grams of copper (II) chloride. A single replacement reaction takes place. What are the likely observations when the

reaction stops?

Unbalanced equation: CuCl2 + Al - AlCl3 + Cu

A .About 0.90 grams of copper (II) is formed, and some aluminum is left in the reaction mixture

B. About 0.20 grams of copper (II) is formed, and some aluminum is left in the reaction mixture

C. About 0.90 grams of copper (II) is formed, and some copper chloride is left in the reaction mixture

D, About 0.20 grams of copper (II) is formed, and some copper chloride is left in the reaction mixture

the correct answer is:

a. formation of precipitation

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.