25 Daniell cell
Exploiter des résultats expérimentaux :

In 1836, English chemist J. Daniell invents the Daniell cell, a kind of battery. During a chemical transformation, zinc Zn(s) reacts with copper ions Cu²+ (aq). At the end of the transformation, the solution is colourless. A red deposit of copper on the zinc can be observed. When an aqueous solution of sodium hydroxide is added to the solution, a white precipitate appears. During this transformation, the temperature increases. Data An aqueous solution of sodium hydroxide allows to test the presence of zinc ions. If a white precipitate appears, the test is positive.

a. Draw the chemical test of zinc ions.

b. Identify reagents and products.

c. Write the balanced equation for the reaction.

d. Identify the limiting reactant.

e. Indicate if this transformation is endothermic or exothermic. ​