Lab 2 Density PDF

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density lab report...

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Data Analysis and Graphing Pre-Lab Questions 1. What can cause the density of the same substance to change?

Change in volume can change the density. Density is inversely dependent upon the volume of the material. The more space molecules take the farther they are from each other, and the closer the molecules are denser is the material.

2. List two possible hazards in this laboratory experiment.

In this experiment, lot of water can be splashed and dropped in the floor with proper care is not administered. Water in the floor makes it slippery which could lead to fall hazards.

Beaker and glass apparatus must be clean and free from oily particles. Accident may happen and they may fall or break into pieces. So proper eye protection is necessary. Gloves is required when working with different types of liquids.

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3. A gold-colored ring is found to weigh 2.542 g at 20 °C. The ring is dropped into a graduated cylinder filled with water and is found to displace 0.33 mL of liquid. If the density of 14 carat gold is 12.9 to 14.6 g/mL at 20 °C, is the ring made of gold? Explain your answer.

Weight of the ring(m) = 2.542 g

Displaced water = 0.33 mL

Since the ring displaced 0.33 mL of liquid, the volume of the ring is 0.33 mL.

Let calculate the density of the ring.

Density = Mass / Volume = 2.542 g / 0.33 mL = 7.7030303 = 7.703 g mL

According to www.chemistry.elmhurst.edu, density of gold is 19.30 g mL, but the density of the ring is 7.703 g mL. Hence it cannot be gold.

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Experiment 1: Determination of Density Data Tables

Procedure 1: •

Mass of Sample Washers: 1.5 = 1.5g gram

•

Initial Volume of Water: 9 mL

•

Final Volume of Water: 9.7 mL

•

Change in Water Volume:0.7 mL

•

Density: M/V = 1.5 g / 0.7 mL = 2.1428 = 2.143 g mL

Table 2: Observation of Plastics Type of Plastic

Location on Column (mL)

Plastic pipe

7.4

60 mL Beaker

15

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Post-Lab Questions 1. What material did you determine your washers are made from? Why did you decide your sample washers are made out of this metal?

The density of the washer came out to be 2.143 g ml. Finding the closest metal with similar density, I found Aluminum (AL) which has the density of 2.7 to be the best fit here.

2. Which is the calcium chloride solution poured into the density column first?

3. Which type of plastic is most dense? Which type is the least dense? Explain.

I only had two types of plastic or toys. I could not gather any more plastic items for the test. Among two, the 60 ml beaker was the dense one because it displaced the most water.

4. How could you use a density gradient column to help identify whether a toy car is made with more metal or more plastic?

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