Answer : The O-O bond in [tex]H_2O_2[/tex] will be longer than the O-O bond in [tex]O_2[/tex].
Explanation :
In the [tex]H_2O_2[/tex], the two oxygen atoms are bonded by the single bond and in [tex]O_2[/tex], the two oxygen atoms are bonded by the double bond.
As we know, the bond strength of double bond is greater than the single bond.
And the relation between the bond strength and bond length is,
[tex]\text{ Bond strength}\propto \frac{1}{\text{ Bond length}}[/tex]
That means the higher the strength, the shorter will be the bond length.
Hence, the bond length of single bond will be longer than the double bond.
The structure of given molecule is shown below.