Article: First, pre-weigh a container. Next, take the weight of the container again, but this time with a specified volume of your liquid inside. Subtract the weight of the liquid-filled container from the weight of the empty container. The difference is the weight of your liquid. For example, if your container weighed 1.50 pounds with liquid in it and 1.00 pound empty, your equation would look like this: "1.50 lb - 1.00 lb = 0.50 lb." Your liquid weighs 0.50 pounds. Make sure the temperature of your liquid is noted when this weight is taken. You must compare it to water of the same temperature. Fill the same container to the same volume. Then, weigh the container and find the weight of that volume of water. You should not need to pre-weigh the container again, since you already know the weight of the empty container. Use the same formula to find the weight of the water. If the liquid-filled container weighted 1.75 pounds, the equation would look like this: "1.75 lb - 1.00 lb = 0.75 lb." In this example, the water weighs 0.75 pounds. Make sure that the water is at the exact same temperature as the liquid in question. Otherwise, results may not be accurate. Since you are dividing one weight by another, the units will cancel out. This makes specific gravity a unitless measurement. Use the ratio "Wl / Wwater" where Wl is the weight of your liquid and Wwater is the weight of water. For example, if you weighed 100 mL of acetone at 25 degrees Celsius, it would weigh 0.17314 pounds. Weighing the same volume of water at the same temperature would give you 0.22 pounds. To find the specific gravity of this acetone, you would solve 0.17314lbs/0.22lbs=0.787{\displaystyle 0.17314lbs/0.22lbs=0.787}. This is the specific gravity of acetone.
What is a summary of what this article is about?
Obtain a weight for the liquid in question. Obtain the weight of an identical volume of water. Calculate the ratio of the liquid's weight to the weight of water.