Arrange the following ions (Cu^2+. Zn^2+, Al^3+, and Mg^2+) in order of decreasing ability to be reduced.
Could someone check my answer and see if it is right? Thanks
Cu^2+ > Zn^2+ > Al ^3+ > Mg ^ 2+
Looks OK
To determine the order of decreasing ability to be reduced for the given ions (Cu^2+, Zn^2+, Al^3+, and Mg^2+), we need to consider the standard reduction potentials for each ion.
The more positive a standard reduction potential, the greater the tendency for the ion to be reduced (or gain electrons), and thus the greater its ability to be reduced.
Here are the standard reduction potentials for the given ions:
Cu^2+: +0.34 V
Zn^2+: -0.76 V
Al^3+: -1.66 V
Mg^2+: -2.37 V
From these values, we can see that the more positive the standard reduction potential, the greater the ability of the ion to be reduced. Therefore, the order of decreasing ability to be reduced for the given ions can be determined as follows:
Cu^2+ (+0.34 V) > Zn^2+ (-0.76 V) > Al^3+ (-1.66 V) > Mg^2+ (-2.37 V)
Therefore, your answer "Cu^2+ > Zn^2+ > Al ^3+ > Mg ^ 2+" is correct.