# Lab Practical Results

```Lab #1
Name:
Lab #1: Introduction to Lab Techniques
INTRODUCTION
Our goals in this experiment are (1) to make some measurements using a metric ruler, (2) to learn how
to determine volumes with a graduated cylinder, and (3) to determine the density of an unknown liquid
and an unknown solid.
PROCEDURE
Part A: The Metric Ruler
i) On the image of the metric ruler below, draw a small arrow pointing to 2.00 cm and write “A”,
do the same and write “B&quot; at 12.00 cm, &quot;C&quot; at 3.50 cm, &quot;D&quot; at 8.55 cm, and “E&quot; at 10.60 cm.
NOTE: The numbers that are displayed are cm, the increment is 0.1 cm.
A
C
D
D
D
E
D
B
D
ii) Use a metric ruler to determine the length and width of this piece of paper. Metric rulers
are on the counter in the back of the lab. Use the correct number of decimal places based
on the ruler increment (as you did in the pre-lab).
Increment on metric ruler = 0.1 cm
Length of the page = 69.5 cm
Do calculations to convert the length of the page to mm and meter
(show your calculations for full credit)
cm to mm
69.5 cm
10 mm
1 cm
= 695 mm
cm to m
69.5 cm
1m
100 cm
= 0.695 m
= 695 mm
= 0.695 m.
Width of the page = 18.9cm
1
Lab #1
Do calculations to convert the width of the page to mm and meter
(show your calculations for full credit)
cm to mm
18.9 cm
18.9 cm
69.5 cm
10 mm
1 cm
cm to m
1m
= 189 mm
= 0.189 m
100 cm
= 198 mm
= 0.189m.
There are three graduated cylinders set up in the lab. Each line on the 1000mL graduated
cylinder represents ten milliliters (note that 1000 mL = 1 L). Each line on the 100mL
graduated cylinder represents one milliliter. Each line on the 10 mL graduated cylinder
represents 0.1 milliliters.
Observe the top of the liquid in the 100 mL cylinder. Note that the liquid surface is curved,
not level. The curved surface is called the meniscus. The volume is always read at the lowest
point of the meniscus. Hold the graduated cylinder so the meniscus is exactly at eye level.
Now raise and lower the graduated cylinder and observe that the volume reading changes as
the cylinder is raised and lowered. Only when your eye is at exactly the same level as the
bottom of the meniscus can you obtain an accurate volume reading. (The error introduced if
your eye is high or low is called parallax.)
Using the correct number of decimal places (as you did in the pre-lab), determine the volume
of liquid in each of the 3 cylinders and record the data below.
Increment of
10 mL
Volume of Liquid
in Cylinder
300mL
1 mL
30 ml
1000 mL (= 1L)
100 mL
10 mL
Remember to use units whenever you write a number.
2
Lab #1
Part C: Measuring the Density of a Solid
1) Each student will be given a metal cylinder, record the unknown number in the data table
below.
2) Weigh the metal cylinder, record the mass (in data table below) to at least three places past the
decimal point.
3) Determine the increment of the 100 mL graduated cylinder and record it in the table below.
4) Place about 30 ml of water in your 100 mL graduated cylinder, record the volume to one
decimal place more precise than the increment (as done in pre-lab) in the data table below.
5) While holding the graduated cylinder at an angle, carefully slide your metal slug into the
graduated cylinder. The metal cylinder must be completely submerged. Record the new volume
in the data table below to one decimal place more precise than the increment.
DATA TABLE
Metal Cylinder: Unknown number: 4a
Mass of metal: 121.221g
Increment on a 1000 ml graduated cylinder 10 mL
(Figure it out just as you did on the prelab or ruler)
Volume before submersion of metal 300mL
(report volume to one decimal place more precise than the increment)
Volume after submersion of metal 350mL (report volume to one decimal
place more precise than the increment)
6) Calculate the volume of your metal cylinder.
Use the data above and the “volume by displacement method”
as discussed in the powerpoint prelab introduction to calculate
the volume of the metal.
Volume of displacement =
Volume final – initial volume = 350 – 300 = 50 mL
= 50 mL
7) Go to page 5 and calculate the density of your metal cylinder. Show your calculations, using the
correct number of significant figurers in the appropriate box on page 5.
3
Lab #1
DATA TABLE
Metal Cylinder: Unknown number: 4b
Mass of stone: 14.459 g
Increment on a 100 ml graduated cylinder 1 mL
(Figure it out just as you did on the prelab or ruler)
Volume before submersion of metal 30mL
(report volume to one decimal place more precise than the increment)
Volume after submersion of metal 35mL (report volume to one decimal
place more precise than the increment)
8) Calculate the volume of your metal cylinder.
Use the data above and the “volume by displacement method”
as discussed in the powerpoint prelab introduction to calculate
the volume of the metal.
Volume final – initial volume = 35 – 30 = 5 mL
= 5mL
9) Go to page 5 and calculate the density of your metal cylinder. Show your calculations, using the
correct number of significant figurers in the appropriate box on page 5.
4
Lab #1
DENSITY CALCULATIONS
In the boxes below, calculate the densities of the metal cylinder and the unknown liquid.
Remember: Every number in a measurement must have a number and a unit)
i) Calculation of the unknown solid’s density (4a)
density = mass
volume
= 121.221g
50mL
= 2 g/mL (1 s.f)
Unknown solid number 4a
Density of your unknown solid: 2 g
Did you use the correct number of significant figures? yes
ii) Calculation of the unknown solid’s density (4b)
density = mass
volume
= 14.459g
5mL
= 3 g/mL (1 s.f)
Unknown liquid number 4b
Density of your unknown liquid: 3 g/mL
Did you use the correct number of significant figures? yes
END OF LAB #1
5
```