Mass and Volume

Density

a

b c

d

e.

Sample

Mass of

Sample,

(g)

Initial

Volume,

(mL)

Final

Volume,

(mL)

Volume

of

sample,

(mL)

Mass/ volume of the sample (g/ mL) (a ÷ d)

Red 1 Red 2 Red 3

AVERAGE XXX XXXXX XXXXX XXX Silver 1 Silver 2 Silver 3

AVERAGE XXX XXXXX XXXXX XXX

Mass & Volume Lab

IV is mass, DV is volume, mass/ volume ratio (density) is the calculated quantity.

READ FROM

THE BOTTOM

OF THE

MENISCUS

Reading a Graduated Cylinder

major

divisions: numbers

minor divisions:

Marks without numbers

Scale read up and in

some cylinders, down

also

Mass and Volume Lab Graduated Cylinders

Red metal

• Use 10 mL cylinder with exactly 5 mL water

added.

Silver Metal

• Use 25 mL cylinder with exactly 14 mL water

added.

Major and Minor Marks on the Graduated Cylinder

1. Define major & minor marks Major mark has a number, minor mark is just a line.

a. What is the value of each minor mark?

b. What is the uncertainty (the

estimation)?

c. What is the measurement?

Subtract two subsequent numbers &

divide by the number of lines in-between.

𝟒𝟎−𝟑𝟎

𝟏𝟎 𝒍𝒊𝒏𝒆𝒔 = 1 mL

Estimation or uncertainty is ½ the minor mark, which is 𝟏.𝟎 𝒎𝑳

𝟐 = 0.5 mL

38.5 mL

Record object’s volume consistent with a graduated cylinder’s limit of precision.

13.0 mL

How many significant

figures?

three

The major marks

are ____ mL 5

The minor marks

are ____ mL 1

Estimation is ½ the

minor mark, which

is 0.5 mL

The measurement is

What is the measurement shown

in cm3?

Reading a Graduated Cylinder Determine the value of

each minor mark

𝟏𝟎−𝟗

𝟏𝟎 𝒍𝒊𝒏𝒆𝒔 = 0.1 mL

What is the uncertainty?

Estimation is ½ the minor

mark, which is

𝟎.𝟏 𝒎𝑳

𝟐 = 0.05 mL

8.85 cm3

The measurement has ___ significant

figures 3

10

9

8

Draw the section of the cylinder in the red

box:

Water Displacement

To the right is a graduated cylinder

containing water.

An object with a mass of 21g and a volume

of 15 mL is lowered into the water.

a. What is the value of each minor

mark?

b. What is the initial volume in the

graduated cylinder?

c. What is the final volume after the object

is placed in the cylinder?

d. What is the water displacement?

Water Displacement a. minor mark =

b. initial volume =

c. final volume =

d. Volume change = water displacement

39.0 mL – 26.0 mL = 13 mL 39

or 13 mL

26.0 mL

50-40/5 = 2mL

39.0 mL

Volume of the

object = the

volume of the

water displaced

Water Displacement

The object place in the water caused the water to rise 15mL. This is the water displacement.

The volume of the object = the water displacement. 39

13 mL or

13 cm3

Volume of

the object

39.0 mL – 26.0 mL = 13 mL

1 mL = 1 cm3

Need 3 Mass Samples of Each Metal Red metal: need 3 samples, each with a different mass.

– Smallest sample >= 4.00g – Largest sample ≈<= 15.00 g

Silver Metal: need 3 samples, each with a different mass

– Smallest sample >= 4.00 g – Largest sample ≈ <= 11.00 g

In multiples of ≈5 g

sample 1 2 3

Approximately: 4.00g – 5.00 g 9.00g – 10.00g 14.00g – 15.00g

Example 1 4.17 g 9.33 g 14.24g

Example 2 4.35 9.65 14.87

Example 3 5.07 10.22 15.11

In multiples of ≈3 g

sample 1 2 3 Approximately: 3.00 g – 5.00 g 6.00 g – 8.00 g 9.00 g – 11.00 g

Example 1 3.17 g 6.33 g 9.24g

Example 2 4.35 7.65 10.87

Example 3 5.07 8.22 11.11

Mass and Volume Lab Graduated Cylinders

Red metal

• Use 10 mL cylinder with exactly 5 mL water

added.

Silver Metal

• Use 25 mL cylinder with exactly 14 mL water

added.

a

b c

d

e.

Sample

Mass of

Sample,

(g)

Initial

Volume,

(mL)

Final

Volume,

(mL)

Volume

of

sample,

(mL)

Mass/ volume of the sample (g/ mL) (a ÷ d)

Red 1 Red 2 Red 3

AVERAGE XXX XXXXX XXXXX XXX Silver 1 Silver 2 Silver 3

AVERAGE XXX XXXXX XXXXX XXX

Mass & Volume Lab

IV is mass, DV is volume, mass/ volume ratio (density) is the calculated quantity.

a b c d e

Sample

Mass of

Sample,

(g)

Initial

Volume,

(mL)

Final

Volume,

(mL)

Volume of

sample, (mL)

(c -b)

𝒎𝒂𝒔𝒔

𝒗𝒐𝒍𝒖𝒎𝒆

(a ÷ d)

Density

1

6.82 10.1 11.2 1.1 6.2 2

8.74 11.2 12.4 1.2 7.3 3

9.8 12.3 13.7 1.4 7.0

AVERAGE: 6.8

Average Experimental

Value of Density

Metal: Magnesi

um

Aluminum Barium Titanium Zinc Copper Lead Hafnium

Density

(g/mL)

1.55 2.70 3.50 4.51 7.14 8.96 11.3 13.10

Accepted Density Values

Use the above accepted values of density to determine the

probable identity of your metal by comparing these accepted

values (shown above) with your experimental density

values for each metal.

Write in your lab book:

According to my experimental density values the red

metal is _________ and the silver metal is __________.

a b c d e

Sample

Mass of

Sample,

(g)

Initial

Volume,

(mL)

Final

Volume,

(mL)

Volume of

sample, (mL)

(c -b)

𝒎𝒂𝒔𝒔

𝒗𝒐𝒍𝒖𝒎𝒆

(a ÷ d)

Density

1

6.82 10.1 11.2 1.1 6.2 2

8.74 11.2 12.4 1.2 7.3 3

9.8 12.3 13.7 1.4 7.0

AVERAGE: 6.8

| exp |% experimental error 100

accepted value erimental valuex

accepted value

Percent experimental error calculation

From your data table, your average density for the your

metal is 6.80 grams/ mL.

This is the experimental value.

The closest value to 6.80 g/mL is zinc.

The accepted value of density of zinc is 7.14 g/ml

% 𝑒𝑟𝑟𝑜𝑟 =| 7.14 −6.80|

7.14 x 100 = 4.76%

Consider your results accurate if the percent error is

equal or less than 10%. Write in your lab book:

Our results are/ are not accurate because _______.

Are Your Results Accurate? • Write one of the following in your lab book

depending on the outcome of your % error

calculation: • Our results are accurate because our % error is

= < 10%.

• Our results are not accurate because our

% error is > 10%.

Use This Calculation to see if Your Data Is

Precise Example:

– Value 1 = 6.2g/cm3,

– value 2 = 7.0g/cm3,

– value 3 = 7.3 g/cm3

highest value - lowest value

% range = -------------------------------- x 100

lowest value

Consider your values precise if the range is less than or equal

to 20%.

% 𝑟𝑎𝑛𝑔𝑒 = 7.3 − 6.2

6.2𝑥 100 = 17.7%

Is Your Data Precise? • Write one of the following in your lab book

depending on the outcome of your % range

calculation: • Our data is precise because our % range is = <

10 %.

• Our data is not precise because our %

range is > 10%.