I have some too but it's probably no good now.
If you've ever poured hydrogen peroxide solution onto a cut and didn't experience the expected fizz, it's likely your bottle of hydrogen peroxide has become a bottle of plain water. The 3% hydrogen peroxide solution you can buy for use as a disinfectant typically has a shelf life of at least a year if the bottle is unopened, but only lasts 30-45 days once the seal has been broken. As soon as you expose the peroxide solution to air, it starts to react to form water. Also, if you contaminate the bottle (e.g., by dipping a swab or finger into the bottle), you can expect the effectiveness of the remaining liquid to be compromised.
Also FYI. Household bleach loses about 50% of it's strength every 12 months.
Any first year cook can do that.
Knowing what is which is the hard part. ;)
'What Johnny thought was H2O was H2SO4', and there goes another student.
/johnny
/johnny