Consider the following standard reduction potentials: E^ _ Ni ²⁺/ Ni = -0.25 V E^ _ Zn ²⁺/ Zn = -0.76 V E^ _ Cu ²⁺/ Cu = +0.34 V E^ _ Ag ^+/ Ag = +0.80 V Which of the following aqueous solutions can be safely stored in a nickel vessel?

Step-by-step solution

For an aqueous solution to be safely stored in a metal vessel, the metal must not react with the solution. This means the metal should not be oxidized by the cations present in the solution. A spontaneous reaction occurs if the standard reduction potential of the cation is greater than that of the metal vessel. Here, the vessel is made of Nickel ( E^ _ Ni ²⁺/ Ni = -0.25 V ). Comparing the E^ values: E^ _ Cu ²⁺/ Cu = +0.34 V > -0.25 V (Reaction occurs) E^ _ Ag ^+/ Ag = +0.80 V > -0.25 V (Reaction occurs) E^ _ H ^+/