Introduction:

Density is the concentration of molecules within an object on relation to its size. The formula for measuring density is mass/volume. In the experiment preformed for this lab report, calculating the density of a regular object (a wooden block) and two other irregular objects (zinc and tin) were found by a process known as water displacement. The purpose of this experiment was to prove that the density of an object remains the same no matter how much of it you have.

Materials: 1. 2. A wooden block 3. A graduated cylinder 4. Sink with running water 5. Ruler 6. A sample of zinc 7. A sample of tin 8. Electronic balance 9. Pencil/ pen and tables

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to record the data

Methods: A. Finding the density of a regular solid 1. Measure the length, width and height of the wooden block, record the data in your table 2. Multiply the length, width, and height to find the volume of the block, record in your table. 3. Use the electronic balance to find the mass of the block. 4. Find the density of the block by dividing the mass by the volume. 5. In this experiment, the density was measured by g/cm3. B. Finding the density of a liquid 1. Measure the mass of the graduated cylinder on the electronic balance and write the number down. Remove the cylinder from the balance. 2. Fill the cylinder with 20mL of water and record this number in your data table. 3. Place the cylinder with the water in the electronic balance, this number will be the mass of the cylinder and the water, however, only the mass of the water is needed so you must subtract the mass of the cylinder from the first step. 4. Divide the mass by the volume of the water so you are left with the density of the water. Record this number in your data table rounded to the nearest whole number. 5. Repeat steps 2-4 with 40mL and then 60mL of water. 6. Use the data from your table to create a line graph of the data. C. Calculating the density of an irregular solid 7.

Measure the mass of the graduated cylinder using the electronic balance. 8. Using the electronic balance, find the mass of the zinc sample. 9. Fill your cylinder with enough water so that when the sample is dropped in, it will be completely submerged (80mL was used in this experiment). 10. Place the cylinder on the electronic balance and drop the zinc in the water. 11. Look at the measurements on the side of the cylinder to find how much the water rose. 12. Subtract the original amount of water from this new number and that will be the volume of the sample. 13. Divide the mass of the sample by the volume and this number will be the density. 14. Repeat 2-7 with the tin sample. 15. To calculate the percent error of the density of the elements, subtract the actual density from the measured density and divide that number by the actual density. Turn that number into a percent by moving the decimal point two places to the right.

Results:

Finding the Density of a Regular Solid Object | Mass (g) | * Length (cm) | Width (cm) | Height (cm) | Volume (cm3) | massvolume | Density (g/cm3) | 1 | 37.9 | 4.5 | 3.9 | 3.3 | 57.9 | 37.957.9 | 0.655 |

Finding the Density of a

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Liquid

Table: Amount of Water (mL) | Mass of Water (g) | massvolume | Density (g/mL) (rounded to the nearest whole number) | 20 | 17.9 | 17.920 | 1 | 40 | 38.6 | 38.640 | 1 | 60 | 57.9 | 57.960 | 1 |

Graph:

Calculating the Density of an Irregular Solid element | Mass (g) | Volume of water (mL) | Volume of water + object (mL) | (Volume of water + sample) - volume of water | Density (g/mL) | Zinc | 18.9 | 80 | 82 | 82 - 80 = 2 | 9.45 | Tin | 13.5 | 80 | 81 | 81 - 80 = 1 | 13.5 |

Percent error:

Zinc: 9.45-7.1347.134=0.325=32.5%

There is a 32.5% error in the calculation of the density of zinc.

Tin: 13.5-7.2877.287=0.853=85.3% There is an 85.3% error in the calculation of the density of tin.

Conclusion:

In conclusion, the data was not accurate. When calculating the percent error, there was a large difference in the accepted density of tin and zinc than what was determined from the experiment. If the experiment were to be preformed again, the volume of the sample should be recalculated to find a more accurate density, less water may be used as well. If the volume of the sample is found to be less than what was concluded in this experiment, then the data will be more accurate. This experiment may also be improved by more than one

trial.