An object made of aluminum has a mass of 8.37g. When it was placed in a graduated cylinder containing 20.0mL, the water level rose to 23.1mL. Calculate the density and the specific gravity of the object.
For the density I got 2.7g/mL, and for specific gravity I got 0.135g/mL. Is this right?
2.70 g/mL is the correct value for density. The specific gravity is NOT 0.135 for two reasons:
1. specific gravity is the same as density if the water had a density of 1.00 g/mL.
2. specific gravity has no units.
The density is 2.7g/mL.
The specific gravity is 2.7
To calculate the density of an object, you need to divide its mass by its volume. In this case, the mass of the object is given as 8.37g, and the volume of water displaced is equal to the difference in the water levels before and after placing the object in the graduated cylinder: 23.1mL - 20.0mL = 3.1mL.
Density = mass / volume
Density = 8.37g / 3.1mL
Let's calculate the density:
Density = 2.7g/mL
Your calculation for the density is correct.
To calculate the specific gravity of an object, you need to compare its density to the density of water. The specific gravity is the ratio of the density of the object to the density of water.
Specific Gravity = Density of the object / Density of water
The density of water is approximately 1g/mL. Let's calculate the specific gravity:
Specific Gravity = 2.7g/mL / 1g/mL
Specific Gravity = 2.7
Your calculation for the specific gravity is correct. The specific gravity of the object is 2.7.
To calculate the density of an object, you need to divide its mass by its volume. In this case, the mass of the aluminum object is given as 8.37g, and the volume of the water displaced in the graduated cylinder is the difference between the final and initial levels of the water, which is 23.1 mL - 20.0 mL = 3.1 mL. Therefore, the density of the aluminum object is:
Density = Mass / Volume
Density = 8.37g / 3.1mL
Density = 2.70 g/mL
So, your calculated density of 2.7 g/mL is correct.
Now, let's move on to the specific gravity. The specific gravity is the ratio of the density of a substance to the density of a reference substance, usually water. In this case, we can use the density of water as a reference, which is approximately 1 g/mL.
Specific Gravity = Density of Substance / Density of Water
Specific Gravity = 2.70 g/mL / 1 g/mL
Specific Gravity = 2.7
So, your calculated specific gravity of 2.7 is also correct. Note that there is no unit for specific gravity as it is a ratio.
Therefore, your answers of 2.7 g/mL for density and 2.7 for specific gravity are correct.