2
one
That is 30 teaspoons.
150 tsp 1 oz = 6 tsp 1 tsp = 0.16 oz
9
Approximately 300 teaspoons depending on the substance,
That is approximately 150 teaspoons
A teaspoon is usually considered to be 5ml, therefore 150ml would be 30 teaspoons
that is approximately 9.8 teaspoons
The answer is 150 mL.
Exactly 150 teaspoons.
If I did my math correctly I believe that you would need 150 teaspoons
You cannot. Mgs (or milligrams) are a measure of mass while teaspoons are a measure of volume. The two are measures of different attributes and, according to the basic principles of dimensional analysis, conversion between the two is not valid without additional information - in this case a measure of density of the substance for which you want a conversion.