1a.
You fill a small graduated cylinder with exactly 10.00 ml of distilled water with a temperature of 20.0oC which weighs 10.00 grams. You pour out the water and put in 10.00 ml of ethanol into the same graduated cylinder which weighs 7.893 grams. What is the specific gravity of ethanol?
density H2O @ 20o C = 10.00g/10.00 mL = 1.000 g/mL
density EtOH @ 20o C = 7.893g/10.00 mL = 0.7893 g/mL.
specific gravity 20oC/20oC = 0.7893 g*mL^-1/1.000 g*mL^-1 = 0.7893 (units cancel so s.g. has no units)
To calculate the specific gravity of ethanol, we need to understand that the specific gravity is defined as the ratio of the density of a substance to the density of a reference substance. In this case, the reference substance is water.
First, we need to determine the density of water at 20.0oC. We can find this information in a density chart or use experimental values. For water at this temperature, the density is approximately 0.9982 g/ml.
Next, we need to find the density of ethanol. To do this, we can use the weight and volume measurements provided.
The difference in weight between the empty graduated cylinder and the one filled with ethanol is (10.00 g - 7.893 g) = 2.107 grams.
Since the volume is 10.00 ml for both water and ethanol, the density of ethanol can be calculated as follows:
Density of ethanol = Weight of ethanol / Volume of ethanol = 2.107 grams / 10.00 ml = 0.2107 g/ml.
Finally, we can calculate the specific gravity of ethanol by dividing the density of ethanol by the density of water:
Specific gravity = Density of ethanol / Density of water = 0.2107 g/ml / 0.9982 g/ml ≈ 0.211.
Therefore, the specific gravity of ethanol is approximately 0.211.