MysticColby
Well-known member
- Joined
- Aug 17, 2011
- Messages
- 425
Background:
I have films that might contain silver. They are 8"x10", used for western blots. I took 1000 of them, put them in a 5-gallon bucket, filled with water, added 100g sodium hydroxide, stirred, waited, added another 100g sodium hydroxide, stirred, waited. When there was no more visible spots on the films, I rinsed them in another bucket of water and pooled the buckets. I let it settle for a week (very slow to settle...), then decanted it through a filter, then transferred the black muck at the bottom into a 1L beaker.
Before I started this, I did some reading. During that time, it was suggested that you could add hydrogen peroxide to silver oxide to convert it to metallic silver (as an alternative to karo syrup).
I wanted to try this, as I've never been able to get karo syrup to work, so I added 100ml 30% hydrogen peroxide to the beaker a little at a time with stirring in between. It bubbled a lot and for a long time and got warm. I let it settle overnight, and now there is about 150ml of silvery/grey powder precipitated. I'm optimistic it's silver.
That's where I am at now. My questions: has anyone else used hydrogen peroxide like this before? how does people's experiences with karo syrup compare? how much hydrogen peroxide is needed? (this time I pretty much just kept adding it until there was much less bubbling from further additions)
edit:
Also, what's going on molecularly? My guess:
silver-halide + NaOH -> AgOH + Na-halide
2AgOH -> Ag2O + H2O
Ag2O + H2O2 -> 2Ag + O2 + H2O
based on this, it's 1:1 silver oxide and hydrogen peroxide.
100g silver oxide / 231.735 g/mol = 0.4315 mol
0.4315 mol hydrogen peroxide * 34.0147 g/mol = 14.678g hydrogen peroxide
14.678g hydrogen peroxide / 1.135 g/ml = 12.932 ml 100% hydrogen peroxide
12.932 ml 100% hydrogen peroxide / 0.3 = 43.1ml 30% hydrogen peroxide
100g silver oxide = 93.096g silver
but silver will increase the rate of decomposition of hydrogen peroxide. how much is required is probably proportional to how quickly you add it.
I have films that might contain silver. They are 8"x10", used for western blots. I took 1000 of them, put them in a 5-gallon bucket, filled with water, added 100g sodium hydroxide, stirred, waited, added another 100g sodium hydroxide, stirred, waited. When there was no more visible spots on the films, I rinsed them in another bucket of water and pooled the buckets. I let it settle for a week (very slow to settle...), then decanted it through a filter, then transferred the black muck at the bottom into a 1L beaker.
Before I started this, I did some reading. During that time, it was suggested that you could add hydrogen peroxide to silver oxide to convert it to metallic silver (as an alternative to karo syrup).
I wanted to try this, as I've never been able to get karo syrup to work, so I added 100ml 30% hydrogen peroxide to the beaker a little at a time with stirring in between. It bubbled a lot and for a long time and got warm. I let it settle overnight, and now there is about 150ml of silvery/grey powder precipitated. I'm optimistic it's silver.
That's where I am at now. My questions: has anyone else used hydrogen peroxide like this before? how does people's experiences with karo syrup compare? how much hydrogen peroxide is needed? (this time I pretty much just kept adding it until there was much less bubbling from further additions)
edit:
Also, what's going on molecularly? My guess:
silver-halide + NaOH -> AgOH + Na-halide
2AgOH -> Ag2O + H2O
Ag2O + H2O2 -> 2Ag + O2 + H2O
based on this, it's 1:1 silver oxide and hydrogen peroxide.
100g silver oxide / 231.735 g/mol = 0.4315 mol
0.4315 mol hydrogen peroxide * 34.0147 g/mol = 14.678g hydrogen peroxide
14.678g hydrogen peroxide / 1.135 g/ml = 12.932 ml 100% hydrogen peroxide
12.932 ml 100% hydrogen peroxide / 0.3 = 43.1ml 30% hydrogen peroxide
100g silver oxide = 93.096g silver
but silver will increase the rate of decomposition of hydrogen peroxide. how much is required is probably proportional to how quickly you add it.