I want to find out what one teaspoon of any particular salt weighs and I'm having difficulties.
First of all, a very polite request to anybody who would like to tell me "it doesn't matter" - I do know that EI is not based on exact measurements, however in this thread I'm looking for a more scientific answer please!
I started by looking up the densities of the usual salts:
Potassium Nitrate KNO3 = 2.109 g/cm3
Monopotassium Phosphate KH2PO4 = 2.34 g/cm3
Potassium Sulphate K2SO4 = 2.66 g/cm3
Magnesium Sulphate Heptahydrate = 1.68 g/cm3
Now to find the volume of a teaspoon. This is where I start running into difficulties. A quick Google gives widely different answers from 3.5 to 5.9 cm3 depending on whether it's an imperial, metric, UK or US teaspoon! I run a quick experiment on my own teaspoon and I figure it's most likely a metric one at about 5 cm3.
So if I multiply the above chemical densities by 5 I should get the weight of each salt in one teaspoon:
Potassium Nitrate KNO3 = 10.5g
Monopotassium Phosphate KH2PO4 = 11.7g
Potassium Sulphate K2SO4 = 13.3g
Magnesium Sulphate Heptahydrate = 8.4g
Now when I empirically test these values by weighing 10 teaspoons of each salt and dividing the result by 10, I get far less than I expected:
Potassium Nitrate KNO3 = <not tested>
Monopotassium Phosphate KH2PO4 = 6.2g
Potassium Sulphate K2SO4 = 6.5g
Magnesium Sulphate Heptahydrate = 5.0g
What's the reason for the huge difference here? Some of these are half the values I would expect - am I doing something wrong?
First of all, a very polite request to anybody who would like to tell me "it doesn't matter" - I do know that EI is not based on exact measurements, however in this thread I'm looking for a more scientific answer please!
I started by looking up the densities of the usual salts:
Potassium Nitrate KNO3 = 2.109 g/cm3
Monopotassium Phosphate KH2PO4 = 2.34 g/cm3
Potassium Sulphate K2SO4 = 2.66 g/cm3
Magnesium Sulphate Heptahydrate = 1.68 g/cm3
Now to find the volume of a teaspoon. This is where I start running into difficulties. A quick Google gives widely different answers from 3.5 to 5.9 cm3 depending on whether it's an imperial, metric, UK or US teaspoon! I run a quick experiment on my own teaspoon and I figure it's most likely a metric one at about 5 cm3.
So if I multiply the above chemical densities by 5 I should get the weight of each salt in one teaspoon:
Potassium Nitrate KNO3 = 10.5g
Monopotassium Phosphate KH2PO4 = 11.7g
Potassium Sulphate K2SO4 = 13.3g
Magnesium Sulphate Heptahydrate = 8.4g
Now when I empirically test these values by weighing 10 teaspoons of each salt and dividing the result by 10, I get far less than I expected:
Potassium Nitrate KNO3 = <not tested>
Monopotassium Phosphate KH2PO4 = 6.2g
Potassium Sulphate K2SO4 = 6.5g
Magnesium Sulphate Heptahydrate = 5.0g
What's the reason for the huge difference here? Some of these are half the values I would expect - am I doing something wrong?