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
- Decide how much solution is needed – 250ml
 - Determine Molar mass of Citric Acid
- According to PubChem this is 192.12g
 
 - Work out how much solid powder is needed
- Given 1 Mol is the molecular weight in 1 litire of water
 
 - We are producing 250ml – so need to weigh out ¼ of the molar mass
- 192.12 / 4 = 48.03g
 
 - So based on the instructions I found for NaCl
 - We need to dissolve 48.03g in 250ml of Water to produce 250ml 1 molar concentration of Citric Acid
 
Safety
- 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.
 - Correctly label the bottle
 - Wear goggles when preparing the solution
 - Wear gloves and Lab Coat
 - Clean Surfaces
 - 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
- Prepare equipment
 - Measure out 250ml Water
 - Fold paper in ½
 - Unfold paper
 - Put paper on scales
 - Ensure Scales are ZERO
 - Weigh out required amount of Citric Acid Powder
 - Pour powder in to flask and stir or move flask around in a circular motion*
 - Pour solution in to suitable container
 - Stick on labels
 - Wash up and dry equipment
 - Wipe down surfaces etc
 - Wash hands
 - 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
