Final answer:
A concentration cell is constructed using aluminum electrodes with different concentrations of Al3+ in the electrolyte. The half-reactions for the corresponding half cells can be written, and the voltage can be calculated using the Nernst equation. The electrode in Half Cell 2, which has a higher concentration of Al3+, will corrode.
Step-by-step explanation:
A concentration cell is constructed by connecting two nearly identical half-cells, each based on the same half-reaction and using the same electrode, varying only in the concentration of one redox species. In this case, both electrodes are aluminum. The half-reactions for the half-cells can be written as:
Half Cell 1: Al(s) -> Al3+ (aq, 0.01 M) + 3e-
Half Cell 2: Al(s) -> Al3+ (aq, 0.9 M) + 3e-
To calculate the voltage generated by the concentration cell, you can use the Nernst equation:
Voltage = (RT/nF) * ln([Al3+ in Half Cell 2]/[Al3+ in Half Cell 1])
Where R is the gas constant, T is the temperature in Kelvin, n is the number of electrons transferred in the reaction, and F is Faraday's constant. Plugging in the values from the question, you can calculate the voltage.
Regarding which electrode will corrode, in a concentration cell, the electrode with the higher concentration of the redox species will corrode. In this case, since the concentration of Al3+ is higher in Half Cell 2 (0.9 M), the electrode in Half Cell 2 will corrode.