Paul Sutton

chemistry

Home Chemistry 4 – Indicators

For some reason, the universal indicator paper I have isn't working properly, it could be as it is quite old.

Nevertheless it does seem that if emersed in Water, the chemicals within leech out. I tried this with a few pieces and it has produced a nice blue colour.

So I am assuming that the liquid produced can act as an acid / alkali indicator.

indicator

So to investigate further. I am going conduct an investigation.

Equipment

  • Test tube rack
  • 2 Test tubes
  • Beaker with indicator solution
  • Dropper
  • Spatula

dropper

Chemicals

Both in powder form.

citric acid and bicarbonate of soda

  • Bicarbonate of Soda
  • Citric Acid

Predictions

  • Bicarbonate of Soda – Should change colour towards Purple (Alkali)
  • Citric Acid – Should change colour towards red (Acid)

Method

  • Add Bicarbonate of soda to 1 test tube
  • Add citric Acid to the other
    • Make a note which is which
  • Using a dropper add some of the indicator to each of the test tubes
  • Note colour

Results

Colour changes noted as follows:-

  • Bicarbonate of Soda – Stays blue
  • Citric Acid – Does turn a very pale pink colour

result

Conclusions

  1. I don't think I had an indicator in the first place, as this was blue,any change in colour would not be very noticeable with the addition of the alkaline bicarbonate of soda.

  2. I would have expected the citric acid to be a clearer colour to indicate acid.

  3. I think my indicator paper is simply out of date due to age.

Recommendations

  1. Repeat part of this experiment using fresh indicator paper, only just use the paper to test the above two chemicals mixed with water. As the paper needs a liquid to work anyway.
  2. Throw old papers away and buy new.

Update

As confirmed on Science forums the indicator paper has degraded and needs to be replaced. So my Hypothesis as to the issue was on the right track.

Links

Tags

#Chemistry,#HomeChemistry

Home Chemistry 3 – Molar Solutions

Last year, I had a go at preparing a known concentration 1M of Sodium Chloride (Salt). Using the instructions at Quora.

In order to some chemicals for future use. I will use the same instructions to create a known concentration of Citric Acid, given I want to test the reactivity between this and various metals, in a similar way to my previous experiment in Home Chemistry 1

Calculations

  1. Decide how much solution is needed – 250ml
  2. Determine Molar mass of Citric Acid
    • According to PubChem this is 192.12g
  3. Work out how much solid powder is needed
    • Given 1 Mol is the molecular weight in 1 litire of water
  4. We are producing 250ml – so need to weigh out ¼ of the molar mass
    • 192.12 / 4 = 48.03g
  5. So based on the instructions I found for NaCl
  6. We need to dissolve 48.03g in 250ml of Water to produce 250ml 1 molar concentration of Citric Acid

Safety

  1. Refer to data sheet – We know that Citric Acid is a Irritant, therefore it would be prudent to stick the CORRECT label on the bottle storing the solution.
  2. Correctly label the bottle
  3. Wear goggles when preparing the solution
  4. Wear gloves and Lab Coat
  5. Clean Surfaces
  6. Wash hands when finished

Equipment

  • Scales or Balance
  • Volumetric Flask *1
  • Stirrer
  • Spatula
  • Paper to write notes
  • Paper to put on scales for powder
  • Funnel
  • Label saying 250ml 1 mol Citric Acid
  • Label giving formula and Molar weight
  • Irritant label

Equipment Replacement

*1 As I don't have a volumetric Flask, I can use a 250 or 500ml Conical Flask

Considerations

My weighing scales are only basic and do not measure to 2 decimal places, there for we can weigh out 48g. As this is for home chemistry, while accuracy is important, we can probably make minor compromises.

Chemicals

  • Water
  • Citric Acid Powder

Method

Read fully first

  1. Prepare equipment
  2. Measure out 250ml Water
  3. Fold paper in ½
  4. Unfold paper
  5. Put paper on scales
  6. Ensure Scales are ZERO
  7. Weigh out required amount of Citric Acid Powder
  8. Pour powder in to flask and stir or move flask around in a circular motion*
  9. Pour solution in to suitable container
  10. Stick on labels
  11. Wash up and dry equipment
  12. Wipe down surfaces etc
  13. Wash hands
  14. Store solution safely

Note the fold in the paper,just makes this easier.

  • You may need to pour small amounts in to the flash, and dissolve before adding more

Further reading and advice

There will be a related thread on Science Forums for this, as I want to double check everything is correct.

Tags

#Home,#Chemistry,#HomeChemistry3,#Molar,#Solution,#CitricAcid

Home Chemistry 2 – Magnesium

In an effort to help improve reactions of the Magnesium ribbon I have at home, I tried cleaning one piece with a sanding block, and a cleaning block used for cleaning vero / stripboards before soldering. I got some advice from Science Forums on this.

The result of can be seen in the photo below, so I have two pieces here for comparison. The difference is clear.

White Vinegar

Tags

#Home,#Chemistry,#Magnesium.#Tarnish,#Cleaning,#HomeChemistry2

Citizen scientists join fight to clean up rivers

This looks like something everyone can really get involved in, monitoring the water quality in rivers and other water. There is more details in a recent BBC Article

I will look in to this and see how to get involved, as it may also be something the Paignton Library STEM Group could get involved with.

Will post updates to my Fediverse for further discussion.

Links

Tags

#Science,#CitizenScience,#Chemistry,#Water,#Quality,#Environment,#BBC

Home Chemistry 1 – Follow up

So just posting a follow up to the experiment with a photo of the test tubes.

Test tubes - final

So we can see From this that the tube on the far left still has Zinc, the one on the Far right has Copper. The centre tube did have the Magnesium, but this is now Magnesium Acetate.

So an interesting experiment.

Testing for Acetate

For those taking a more scientific approach and who may want to test to confirm what is produced the following from Robolab may be useful.

Further reading

I have started a thread on Scienceforums to ask how to decontaminate the other metals. They may need this but it would be good practice not to simply remove from test tubes, leave to dry and put back in the original containers.

Feel free to discuss further on Mastodon. My profile is at https://qoto.org/@zleap

Tags

#Science,#HomeChemistry,#Chemistry,

Home Chemistry 1

A few days ago I was having a look what would happen if various metallic elements were added to a beaker of Distilled White vinegar.

Using Zinc (Zn) didn't appear to do very much, however dropping Magnesium (Mg), did appear to produce a slow reaction, which seemed to result in the magnesium dissolving.

So the experiment I am going to carry out will use the following:

Equipment

  • Test Tube Rack
  • 3 Test tubes

White Vinegar

Elements

  • Zinc Granuals (Zn)
  • Copper Foil (Cu)
  • Magnesium Ribbon (Mg)
  • Distilled White Vinegar

White Vinegar

Other

  • Universal indicator paper

This is not strictly needed, but will be used to test the pH of the vinegar before I start.

Method

  1. Part fill each test tube with White Vinegar
  2. Place 1 sample of each element in a test tube.
    • Note Copper foil and magnesium ribbon should be cut to size.
  3. Place out of the way for a period of time and monitor results

Notes

Experiment started 14:13 on 03/01/2023

Tags

#Home,#Chemistry,#HomeChemistry1

300th Birthday: Axel Fredrik Cronstedt & Biodegradable Plastic

Just sharing these posts posted by Chemistry Views on Mastodon.

Axel Fredrik Cronstedt is credited with the discovery of the Metallic Element Nickel, and is also considered the considered a founder of modern mineralogy.

In other news “Biodegradable High-Density Plastics: Polyethylene-like material can be composted industrially and hydrolyzed by enzymes”

Links

Tags

#Chemistry,#Minerology,#Nickel,#AxelFredrikCronstedt,#Plastic, #Biodegradable,#Enzymes,#Environment

Expanded Functional groups in Organic Chemistry

Compound Chemistry have some really good resource. From time to time some of these are expanded with even more information.

fuctional groups

Adds some more functional groups what is already a really good resource.

Tags

#Science,#Chemistry,#OrganicChemistry,#FunctionalGroups,

Making chemical solutions

An important part of Chemistry is the ability to make up solutions of a known concentration. This can sound quite complex, however it doesn't need to be.

The following is some simple instructions that will produce 250m of 1molar concentration of Sodium Chloride

I have made this solution up using pure Sodium Chloride, from a chemical supplier [1], rather than table salt which contains Sodium Ferrocyanide. If you need extra help with this try asking on Science forums [2] as there is a section on there for home chemistry.

I am also on the IRCNow network, where we are starting up a channel to discuss amateur / home science.

Links

1 Better Equipped 2 Science Forums 3 Amateur Science

Tags

#Chemistry,#NaCl,#SodiumChloride,#Molar,#Mol,#Solution,

Latest FutureLearn course

I signed up to another FutureLearn course, “Atmospheric Chemistry : Planets and life beyond Earth” a few weeks ago.

Mostly for personal interest, however, parts of this will tie in with the National Curriculum.

This is a 4 hour course, spread over 2 weeks, I took my time to compete this as I had other things to do at the same time.

Links

23/5/2022

This course is now complete.

Tags

#FutureLearn,#Chemistry,#Planets,#Atmosphere, #BioChemistry,#Chemistry