Name __________________________ Date _____________ Period _______
UNIT 1: MATTER
#1
Pre Lab Information
Define the following terms:
Definition
Mass
Volume
Density
Salinity
Remembering how to calculate density!
What is the formula for calculating density?
Density = ______ / ____________
What is the standard unit for:
Mass ____________
Volume ________ or _________
ruler
cylinder
Therefore, the standard unit for Density is
___________________
if calculating volume with a ruler
____________________
if determining volume with a cylinder
Saltwater Density Lab Sheet
Question: ______________________________________________________________________.
Hypothesis: If salt is added to water, then the density of the water will_____________________.
Think about it: Will you be changing the mass or the volume????
(increase or decrease)
1. The mass of the empty beaker = ____________
(use unit)
Remember to include the units: Mass is g --- Volume is mL – Density g/mL
÷
DATA
TABLE
Fresh water
Mass of Water
═
Density
Volume of water
3.
2.
4.
8.
2.
9.
Saltwater
Question 1: Did the egg float in the fresh water?
Yes
No
Question 2: Did the egg float in the salt water?
Yes
No
Question 3: Which beaker had a higher density?
Fresh water
Saltwater
Question 4: What changed in the water to make the egg float?
______________________________________________________________________
Question 5: Rank the egg, fresh water, and saltwater based on their density.
Most Dense
______________, ______________, ______________
Least Dense
Question 6: Humans float easily in the Dead Sea. Give two reasons why you think this is possible?
1._____________________________________________________________________________
2. ____________________________________________________________________________
Procedure: Read and complete all of the directions below.
Write the question and hypothesis on your lab sheet.
Question: How does salinity change the density of water?
Hypothesis: If salt is added to water, then the density of the water will _________
(complete this statement on your lab sheet)
Procedures:
1. Measure the mass of the empty beaker; record on lab sheet
2. Pour 200 mL of fresh water into the beaker; record this volume in the volume column
in both fresh and salt water rows of the data table.
3. Follow the directions below to determine the mass of the fresh water:
A. Measure the mass of the beaker with the water.
B. Subtract the mass of the empty beaker (see #1).
C. Record the mass of the fresh water on the data table.
mass of beaker
with water
mass of
empty beaker
mass of
water
4. Calculate the density of the fresh water, Mass ÷ Volume; record density on data table
5. Gently place the egg in the beaker. Answer Question 1
6. Take the egg out of the water and set it on the paper towel.
7. Add 4 rounded spoons of salt to the water – stir gently until dissolved.
8. Follow the directions below to determine the mass of the salt water:
A. Measure the mass of the beaker with the salt water.
B. Subtract the mass of the empty beaker (see #1)
C. Record the mass of the saltwater on the data table.
9. Calculate the density of the saltwater, Mass ÷ Volume; record density on data table
10. Gently place the egg in the saltwater. Answer Questions 2 – 6.
11. Clean Up: Pour salt water into the sink, rinse and dry the beaker.