If I added 60 drops of water to a beaker and weighed it, and then added another 60 drops of water to the breaker;
How would I calculate number of drops per gram.
How do I use density to calculate the number of drops per mL?
record the beaker with the sixty drops weight. Then weigh after the second sixty drops is added.
density=volume/mass= sixty drops/changeinmass
that will give you the density in drops/gram
if you want grams per drop, then do the reciprocal.
changeinmass/60.
Now, for drops per ml. You know the density of water, 1g/ml. So the change in weight you recorded for the second sixty drops is = change in ml.
60/changeinml (same as change in grams).
#drops x (grams/drop) = grams.
You know # drops. You know grams. Calculate grams/drop and take the reciprocal.
Since mass = volume x density you can calculate the volume of the 120 drops.
Then if 120 drops = xx mL, how many drops per 1 mL.
You must remember that the number of drops in a mL will depend upon how the drop is added; i.e., it will be different from an eye dropper than it is from a teflon coated tip of a buret.
The OLD glass tipped buret I used years ago gave very close to 20 drops/mL. Through the years the tip was refined and it was about 25 drops/mL. With the teflon coated tips and smaller tips, it is about 30 drops/mL now.
I would add one caveat to Bob Pursley's response. Check the density of water at the temperature of the water being dispensed by drops. The density may not be significantly different from 1.00 g/mL but it won't hurt to check it and see if it makes a difference.
To calculate the number of drops per gram, you would need to measure the mass of the water added using a balance. Let's say the mass of the water added is X grams.
To find the number of drops per gram, you need to determine the average volume of each drop of water. This can be done by counting the number of drops in a known quantity of water and then dividing that by the volume of that quantity.
For example, if you count 100 drops in a 10 mL graduated cylinder, you would have an average volume of 0.1 mL per drop. Now, to calculate the number of drops per gram, divide the volume (in mL) of X grams of water by the average volume per drop.
Let's suppose the average volume per drop is 0.1 mL. So, if you added X grams of water, which has a volume of X mL (using the density of water, which is approximately 1 g/mL), you would divide X by 0.1 to find the number of drops per gram.
To calculate the number of drops per mL using density, you need to know the density of water. The density of water is roughly 1 g/mL, which means that 1 mL of water has a mass of 1 gram. This information can be used to convert between mass and volume.
You can use the number of drops per gram calculated earlier, and multiply it by the density of water (1 g/mL) to find the number of drops per mL. This calculation is based on the assumption that the density of the water drops is similar to that of pure water.
Remember, these calculations assume that the drop size and liquid density remain constant throughout the experiment.