There can be no equivalence.
A milligram is a measure of mass. A millilitre is a measure of volume. The two measure different things and, according to basic principles of dimensional analysis, conversion from one to the other is not valid.
If you are not convinced, consider a millilitre of air. How many milligrams? Next consider a millilitre of water. How many milligrams?
The masses of equal volumes of the two substances will clearly be very different. So there is no direct conversion between mass and volume: you need to know the density of the substance to enable you to carry out the conversion.
Many people believe that there is an exact conversion for pure water: that is not true. It is only an approximation and that has been the case since 1964 when the definition of the litre was changed.
To make 50 ml of a solution with a concentration of 500 mg per 5 ml, you would need to calculate the total amount needed: 50 ml / 5 ml = 10 units of 5 ml that are needed. Since each unit of 5 ml requires 500 mg, you would need 10 units x 500 mg = 5000 mg. To find out how many 250 mg tablets are needed to make 5000 mg, you would divide 5000 mg by 250 mg per tablet, which equals 20 tablets needed.
if water, 250 Mg = 250 megagrams (i'm not sure that's what you mean) 250 Mg (megagrams) = 250,000,000 ml 250 mg (milligram) = 0.25 ml 250 ug (micrograms) = 0.00025 ml
That would depend upon the density, because mg is a unit of mass, while ml is a unit of volume.
It looks like the 3.5 ml may be extraneous information. If 1 ml yields 250 mg, then you need 400/250 = 1.6 ml, to get 400 mg.
Does not convert; milligrams (mg) and grams (g) are measures of weight or mass and mL (milliliters) is a measure of volume.
how many teaspoons in 250 ML dry
Two
250 mL = about 8.5 US fluid ounces.
This cannot be sensibly answered. A milliliter (mL or ml) is a measure of volume, grams (g), kilograms (kg) and milligrams (mg) are measures of weight or mass.
This cannot be sensibly answered. A milliliter (mL or ml) is a measure of volume, grams (g), kilograms (kg) and milligrams (mg) are measures of weight or mass.
20 tablets are necessary.
16 ml