Question

**CHE101: Module 1 Lab**

**Density - A Characteristic Property**

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Experiment 1

1. You have taken measurements of three volumes of water. Record the following masses for each of the three measurements (in grams):

**a**

graduated cylinder alone (g)

54g

54g

54g

**b**

graduated cylinder plus the water inside (g)

64g

74g

84g

**c**

net mass of the water (g)

10g

20g

30g

2. For each of the three measurements, record and calculate the following. Note that a cubic centimeter (cm^{3}) is equivalent to a milliliter (mL).

**a**

total volume of water (in mL or cm^{3})

10mL

20mL

30mL

**b**

total mass of water (g)

64g

74g

84g

**c**

density of the water (g/cm^{3} or g/mL)

6.4g/cm^{3}

3.7g/cm^{3}

2.8g/cm^{3}

3. Calculate the average of the three density measurements for water.

6.400g + 3.700g + 2.800g = 12.90g

12.90g / 3 = **4.300g**

Experiment 2

1. You have taken measurements of three volumes of ethanol. Record the following masses for each measurement (in grams).

**a**

graduated cylinder alone (g)

54g

54g

54g

**b**

the graduated cylinder and ethanol sample (g)

61.893g

69.786g

77.679g

**c**

net mass of the ethanol sample

10g

20g

30g

2. For each of the three measurements, record and calculate the following:

**a**

total volume of ethanol (mL or cm^{3})

10mL

20mL

30mL

**b**

total mass of ethanol (g)

10g

20g

30g

**c**

density of the ethanol sample (g/cm^{3} or g/mL)

6.189 g/cm^{3}

3.489 g/cm^{3}

2.589 g/cm^{3}

3. Calculate the average of the three density measurements for ethanol.

6.189g + 3.489g + 2.589g = 12.267g

12.267g / 3 = **4.089g**

Experiment 3

1. Record the initial volume of water and the initial mass of the graduated cylinder with water.

Water Volume = 30g

Mass= 84g

2. For each of the iron measurements, record and calculate the following:

**a**

total volume in the graduated cylinder of the water and metal (mL or cm^{3})

30.64mL

31.27mL

31.91mL

32.54mL

33.18mL

**b**

net volume of the iron (mL or cm^{3})

0.64mL

1.27mL

1.91mL

2.54mL

3.18mL

**c**

total mass of the iron (g)

5g

10g

15g

20g

25g

**d**

density of the iron (g/cm^{3} or g/mL)

7.812 g/cm^{3}

7.874 g/cm^{3}

7.853 g/cm^{3}

7.874 g/cm^{3}

7.861 g/cm^{3}

3. Calculate and record the average density of the iron. Express your results in grams/cm^{3}.

7.812g + 7.874g + 7.853g + 7.874g + 7.861g = 39.274

39.274g /4g= **9.818g**

4. For each of the aluminum measurements, calculate and record the following.

**a**

total volume in the graduated cylinder of the water and aluminum (in mL or cm^{3})

31.85mL

33.70mL

35.56mL

37.41mL

39.26mL

**b**

net volume of the aluminum (mL or cm^{3})

1.85mL

3.70mL

5.56mL

7.41mL

9.26mL

**c**

total mass of the aluminum (g)

5g

10g

15g

20g

25g

**d**

density of the aluminum (g/cm^{3} or g/mL)

2.702 g/cm^{3}

2.702 g/cm^{3}

2.697 g/cm^{3}

2.699 g/cm^{3}

2.7g/cm^{3}

5. Calculate and record the average density for the aluminum. Express your results in grams/cm^{3}.

2.702g + 2.702g + 2.697g + 2.699g + 2.699g= 13.499g

13.499g / 4= **3.374g**

6. Use Excel to graph the volume (x-axis) versus mass (y-axis) for both of the metals, separately. Find the equation for a straight line that represents your measured data of the form y = mx + b. The density from all of the measurements is given by the slope, and you should expect the intercept b to be zero, meaning that a sample of zero volume should also have zero mass. Record the slope and intercept values here. Submit your Excel spreadsheet with the two graphs.

Iron Slope is 7.9365

Aluminum Slope is 2.703

Experiment 4

1. Record the initial volume of water and the initial mass of the graduated cylinder with water.

Vol. Of Water = 30mL

Mass of cylinder= 84.000g

2. For each of the incremental additions of the unknown metal, calculate and record the following:

**a**

volume in the graduated cylinder of the water and unknown metal (mL or cm^{3})

30.70mL

31.40mL

32.10mL

32.80mL

**b**

net volume of the unknown metal (mL or cm^{3})

1.4mL

2.10mL

2.10

2.80

**c**

mass of the unknown metal (g)

10g

15g

20g

25g

**d**

density of the unknown metal (g/cm^{3} or g/mL)

7.142 g/cm^{3}

7.142 g/cm^{3}

7.142 g/cm^{3}

7.142 g/cm^{3}

2. Calculate and record here the average density of the unknown metal. Express your results in grams/cm^{3}.

7.142g + 7.142g + 7.142g + 7.142g = 28.568

28.568g / 4g = **7.142g**

3. Can you identify the unknown metal as one of those listed below? The following is a chart of the literature values for the densities of some standard metals.

Aluminum 2.643 g/cm^{3}

Brass 8.553 g/cm^{3}

Copper 8.960 g/cm^{3}

Iron 7.658 g/cm^{3}

Lead 11.370 g/cm^{3}

Magnesium 1.700 g/cm^{3}

Silver 10.500 g/cm^{3}

Steel 7.850 g/cm^{3}

Zinc 7.049 g/cm^{3}

Zinc