Hi all,
Here's a little situation I find a little interesting. I was following a procedure for an old ammonia based MQ developer for autochrome plates. I noticed that quite a lot of precipitate was formed after adding the hydroquinone. Assuming I must have done something wrong, I tried again. And a third time. The third time I added the ingredients in the following order to 400mL of water:
1. 5g Metol (waited until it was fully dissolved)
2. 50g Sodium Sulfite (waiting until it was fully dissolved)
3. 3g KBr (waited until it was fully dissolved).
In a separate 100mL container I added 2.5g Hydroquinone and allowed it to fully dissolve.
After I added the hydroquinone solution to the main one, I initially felt triumphant, as the solution remained clear. However, after about a minute, it grew cloudy and a bunch of precipitate fell out of the solution.
I heated the solution to 55C, and the precipitate dissolved away. It returned once the solution cooled.
Ultimately, it seems like this is somewhat similar to the proper preparation of metoquinone, which can be found here, though they add the sodium sulfite last.
Anyway, I just thought it was kind of funny, since I was thinking about trying to make metoquinone on its own in a few weeks or so. I guess the only reasonable way to confirm would be to wash the crystals and hit it with a melting point test? Thoughts?
Here's a little situation I find a little interesting. I was following a procedure for an old ammonia based MQ developer for autochrome plates. I noticed that quite a lot of precipitate was formed after adding the hydroquinone. Assuming I must have done something wrong, I tried again. And a third time. The third time I added the ingredients in the following order to 400mL of water:
1. 5g Metol (waited until it was fully dissolved)
2. 50g Sodium Sulfite (waiting until it was fully dissolved)
3. 3g KBr (waited until it was fully dissolved).
In a separate 100mL container I added 2.5g Hydroquinone and allowed it to fully dissolve.
After I added the hydroquinone solution to the main one, I initially felt triumphant, as the solution remained clear. However, after about a minute, it grew cloudy and a bunch of precipitate fell out of the solution.
I heated the solution to 55C, and the precipitate dissolved away. It returned once the solution cooled.
Ultimately, it seems like this is somewhat similar to the proper preparation of metoquinone, which can be found here, though they add the sodium sulfite last.
Anyway, I just thought it was kind of funny, since I was thinking about trying to make metoquinone on its own in a few weeks or so. I guess the only reasonable way to confirm would be to wash the crystals and hit it with a melting point test? Thoughts?
