Test solutions

Stannous Chloride

1G stannous chloride granules

1G pure tin (shot)

25ml Distilled Water

30 Drops hydrochloric Acid

Date the bottle with dropper - it only lasts 3mo.

(You will want test solutions of Au PT and PD - 0.2G of each in aqua regia - PD in nitric only - then dilute with 100ml of dist-H₂O

Ammonium Thiocyanate

Turns bright blood red with iron.

DMG (Dimethylglyoxime)

Precipitates PT and PD.. z

Chemistry supplies

Fume Hood -

Wheaton drip tip bottles

Addition funnel - seperatory funnel

condensors

Processes

Test for gold plate

Drop of nitric acid will show the base as the plate is very thin - bubbles + color change.

Precipitating gold from aqua rigia

Sodium Metabisulfite (stumpout)

Sodium Bisulfite

First, add some pure gold to consume any excess nitric acid..

Add till all has precipitated - Stannous test.

Multiple washes with hot dist- water

Boil with hydrochloric acid wash

multiple hot dist-waterr washes.

Decant - dry - remelt

Recover gold from gold plate Iodine-iodie leach

Leach solution - 40g of KI in 400ml distilled water - add 10g of elemental iodine

Add leach solution to plated gold - agitate constantly for 5 min.

decant liquid off with distilled rinse.

Add KOH flakes to solution KOH + I₂ + I₃- = KI + KIO₃at PH > 12.5 Au precipitates + base metals

Fritted glass filtration removes the metals - rinse with dw

(Add formic acid to solution to regenerate the leaching solution. )

Wash metals with HCl - dilute? Removes base metals

Boil with hydrochloric acid (use the waste wash to recgenerate leachin solution)

Wash with boiling distilled water

dissolve with Aqua-regia

filter

drop gold with Sodium Metabisulfite

Melt and cast

Recover gold from gold plate bad method - takes too much nitric acid

Burn off the material with torch

dissolve base metals with nitric acid

Poor off and filter off nitric acid with rinse

Add hydrochloric acid and incremental nitric acid until gold is dissolved

Percipitate gold with Sodium Metabisulfite

Filter out gold

Wash with boiling distilled water

Boil with hydrochloric acid

Wash with boiling distilled water

Melt and cast

Gold with OTC materials

Melt with enough silver to quarter the gold with sterling silver and drop in water to form granules. Press extra thin.

Put in very tall beaker Add 93% H₂SO₄ drain cleaner - heat to boil 138°C

Test with a few drops into 50/50 dilute Hydrochoric acid (HCL) for silver cloride

Boil 4 hours.. cool - decant - add more H₂SO₄ repeat

Repeat. Total of 5 times.until no silver chloride cloud.

Rinse with distilled water

Rinse with hydrochloric acid - then heat to boil

With a add funnel - drip H₂O₂hydroponics 29% - should dissolve gold.

Filter solution - stanic acid test - should see gold.

Add Sodium metabisulfite Na₂S₂O₅ SMB (Bonide's Stump-out) until stannic test goes clear. boil off reagents

Settle gold over-night. decant - wash

Redissolve gold - Add HCl again - heat to boil - drip H₂O2

Add a few drops of H₂SO₄ to percitpitate out any lead.

Filter

Prepare Iron sulfate - dissolve in distilled water - add Hcl until green? filter.

add to solution to precipitate only the gold. - stannous test to be sure all gold has dropped.

Decant waste

Wash with water . Wash with Hcl multiple till clear..

You can redissolve gold a third time.. repeat.

You can also drop gold by dropping H₂SO₄on SMB/water slurry - bubble through H₂SO₄ - makes SO2 gas - bubble through solution to drop the gold. Boil to get rid of SO2 gas.

Wash one more time in HCl - then boil in HCl - decant - wash in distled water.

Cleaning Glassware

Test for neutral PH Bromothymol Blue Solution

Super clean

Bake at 500C

Wash with 10 - DW 10 HCL 1 HNO₃Heat overnight covered with cold cover to form a reflux - rinse DW

Silver test solution

0.5G of Potasium dichromate + 10ml DW and 7ml of 70% nitric acid.

A drop makes some red stuff on real silver - marks the silver..

Electroless Tin plate of copper

Tin - from coreless lead free solder - must be 90%+ tin

1G tin + 10ml 30% HCL - wait till dissolved.. Decant for the liquid. which is Stannous chloride is tin(II) chloride, SnCl₂

add 100ml of silver polish that contains Thiourea mix - heat if not clear.. Will oxidize so seal well.

Remove silver tarnish (sulfur )

200ml water + 20g NaCL (table salt) + 10G NaHCO₃

Connect neg to the silver and + to the liquid..

Make Dimethyl Dioxane from Propylene glycol

distill off water - starts at 180C

800mL of propylene glycol - add 50ml of concentrated H2SO4

Distill with a drop every 2-3 seconds - Remove water layer with seperatory funnel

Add 40g potassium hydroxide to destroy impurities. Stir over night -

Long column - distill off Dimethyl Dioxane - store over sodium

Glassware

Annealing

Bends at about 600°C
annealing

Glass Joints

Most common is 24/40 ( first number is the large end diameter - second the length) Taper is 1:10 where for 10mm of length, diameter changes by 1mm.

Reflux columns Fractional distillation

3rd Century Distillation

columns

Surface area varies and the liquid gas interface varies between types. (The term 'separation efficiency' is quite misleading - it means how well it separates. )

Dufton-Widmer: Glass column with a central, cooled finger creating reflux that travels down a spiral path.

Pros: Moderate efficiency, visual observation possible, defined reflux path.

Cons: More complex glassware, lower efficiency than good packing, fragile.

Pick When: Moderate efficiency is needed and visual monitoring is beneficial. Less common today.

Vigreux: Most often used. : Glass column with downward-pointing indentations.

Pros: Simple, inexpensive, easy to clean, no moving parts/packing. Good for simple distillations.

Cons: Low efficiency (low Theoretical Plates Per Meter - TPM), relatively slow.

Pick When: Cost/simplicity is key, separating components with large boiling point differences, or for educational demonstrations.

Relleno (packed) Column: Empty tube filled with inert packing material (Raschig rings, helices, saddles). Has a very high TPM - better separation.

Pros: High efficiency (high TPM) for its size, relatively simple design.

Cons: Can flood/channel, high pressure drop, packing can be messy to handle/clean, requires careful setup.

Pick When: High separation efficiency is critical, and you can manage packing. Common in labs and small-scale production.

Snyder: Sectioned glass column with bulb-shaped chambers containing free-moving (usually teflon) valves that open/close with vapor flow.

Pros: Good efficiency (TPM), automatic fraction management, reduces flooding, easy to use.

Cons: Sections can be tedious to assemble/clean, valves can stick or break, moderate cost.

Pick When: Reliable, good efficiency for routine fractional distillation in the lab. Popular for solvent purification.

Overshaw Metal (usually) distillation column with perforated plates (trays) and downcomers, mimicking industrial columns.

Pros: High efficiency (TPM), high throughput/capacity, robust, scalable.

Cons: Complex, expensive, harder to clean, requires significant height.

Pick When: High efficiency, high capacity, and robustness are required (pilot plants, larger-scale lab, specialized separations).

Short path Distillation apparatus.

The name comes from having a short diffusion path. The path is short to allow vapor to diffuse without requiring boiling to push the solvent vapor over.You don't need to boil to distill Vacuum helps - why they have vacuum connection. Mostly for delicate oils. Sometimes used to keep the temperatures low enough to prevent decomposition. Use with vacuum helps as less molecules to delay the diffusion.

Drawbacks - Easy to exceed the capacity(rate) of the column (loss via vapors).

Dean-Stark Trap

Two types - light return vs heavy return - used for azeotropic distilation where fractional distillation doesn't work. Often used to remove water.

Fractionating column with a side tube that slants up to a condensing tube. You need a solvent that doesn't bump, splash or foam.

Light return - Traps Heavy

Provides heavy return mode - returns the lighter phase while keeping the heavy phase.

Clevenger Apparatus -Heavy return mode - traps light.

Can sort of do both heavy and light return if you get the middle connected cross tube.

Fractionating column with a side tube that slants up to a condensing tube.

Soxhlet Extractor

Can be used with vacuum.

Soxhlet extraction is application - desired compound has a limited solubility in a solvent, and impurity is insoluble in that solvent. Automates recycling a small amount of solvent to dissolve a larger amount of material. Goes between the boiler and reflux column.

Silver Cell

Recipes

Nitric Acid

2 mol sodium nitrate (170g) meat curing salt

2mol 98% sulfuric acid (207g)

Heat to below 200°C

Distillation - seal with teflon tape.

Sodium magnesium oxide aggregate

30g magnesium powder Mg

40g sodium hydroxide NaOH

Mix in steel container - or crucible cover with brick -prevent oxygen - will eat sodium - ignite

2Mg +2NaOH→ 2MgO + 2Na + H₂

Cover with mineral oil

1,4-dioxane from antifreeze (ethylene glycol)

300ml antifreeze - concentrate (CH₂OH)₂

30ml H₂SO₄ 98% - Can be drain cleaner or more dilute

Distillation apparatus to product start heat and cooling until starts to boil Adjust for a drop every 2-3 sec

Stop when foaming is a problem - you will have water and side products to get rid of (clean with NaOH)

Add 10ml H₂SO₄ 98%

Set up fractional distillation apparatus and start distilling.

Change out the receiver at 84°C

Dioxane and water have a low boiling azeotrope at 87°

Stop at 94° You will have 17.9% water and 82.1% dioxan

Add a bit of Na metal if you can - or the Sodium magnesium oxide aggregate stir over night bubbling should stop.

Distill over the dioxane. Store over sodium or NaOH if you don't have Na metal.. (can blow up on storage otherwise.. )

Potassium Permanganate

From greensand iron filter regenerate

Sodium Metal

Erlenmeyer flask insulated with foil -

14g magnesium powder

20g sodium hydroxide NaOH

2g Menthol crystals

125ml Mineral oil (hypoallergenic baby oil)

3g Na - or as Na MgO aggregate - 8g?

Magnetic stir bar

Top of flask to thermometer and bubbler - using mineral oil prevent backflow and monitors.

Maintain 120 - 130°C This drys the NaOH via the sodium producing hydrogen - wait till 1 bubble every 10sec or slower.

Raise to 200°C - more bubbles.. 15 - 50 hr. bubbling will stop.

Set up reflux on top - add 150ml of 1,4-dioxane - boil with hard stirring for about 2 hr. - let cool sodium should float

Let cool - poor off through sieve to collect - wash with mineral oil

Sulfur dioxide gas

Most convenient way:

Set up gas adapter and a pressure equalized dripping funnel.

100ml water - add 95g Sodium Metabisulfite
120ml of 30% HCl in dripping funnel.

Potassium Permanganate

You can buy this already made as greensand iron filter regenerant

43g of manganese dioxide, often obtained from greensand filter media, and 25g of potassium chlorate, the chemicals are thoroughly mixed. A can made of iron is chosen as the reaction vessel due to its resistance to the highly corrosive mixture.

All reagents are mixed along with 40mL of water and 60g of potassium hydroxide. The can is placed in a furnace and heated to 400 degrees Celsius for several hours. This step involves the oxidation of manganese dioxide to potassium manganate by potassium chlorate, with potassium hydroxide providing essential potassium ions and alkaline conditions. Once cooled and soaked in 300ml of water, the solid chunks of potassium manganate are retrieved. 3K₂MnO₄+ KCl + 3H₂0

To convert potassium manganate into potassium permanganate, chlorine gas is used. A chlorine generator comprising 45g of trichloroisocyanuric acid in 100mL water and 75mL of 30% hydrochloric acid is employed to produce chlorine gas, which is then introduced into the potassium manganate flask. The reaction results in potassium permanganate with potassium chloride as a byproduct. Once the reaction is complete, the mixture is vacuum-filtered and then chilled to separate potassium permanganate from potassium chloride and hypochlorite. The potassium permanganate crystals are beautiful black needles. The final yield is approximately 30.7g or 39%, adjusted to 52% considering the purity of the manganese dioxide used. Both crystallizations of potassium permanganate are found to be 99% pure with a 1% margin of error, confirmed through titration.