NAME:
DATE:
CLASS:
SCIENCE 9: ATOMS & ELEMENTS: Density of Gas Activity
PURPOSE:

to determine the density is of a gas.

to identify the gas based on its density.
THEORY:


A characteristic physical property is a property that can be used to identify a
substance.
The density of a substance is a comparison of its mass to its volume.
𝐷𝑒𝑛𝑠𝑖𝑡𝑦 =



𝑀𝑎𝑠𝑠
𝑉𝑜𝑙𝑢𝑚𝑒
or
𝐷=
𝑚
𝑉
Mass is a measurement of how much “stuff” (matter) makes up an object
o measured using units of: grams (g), kilograms (kg)
o 1 g = 1 ml of water
Volume is a measurement of how much space an object occupies.
o measured using units of: cubic centimeters (cm3), milliliters (mL), litres (L)
o 1 ml = 1 cm3
Measuring: the last digit of a measurement should be an estimate.
o graduated cylinder: estimate whether the volume is exactly on the line
(2,4,6,8,0) or between the lines (1,3,5,7,9)
o electronic balance: use the value reported by the balance to 2 decimal places
APPARATUS & PROCEDURE: (sketch the apparatus and explain how it was used)
Materials: graduated cylinder, triple beam balance, gas collection apparatus, beaker, alka
seltzer tablet
NAME:
DATE:
CLASS:
DATA:
1. Mass of: beaker+test tube+water+tablet
BEFORE
2. Mass of: beaker+test tube+water+contents
AFTER
3. Mass of Gas produced = #1 - #2
4. Volume of Gas collected
grams
grams
grams
mL
CALCULATIONS:
Mass of Gas (g)
Volume of Gas (g)
Density of Gas (g)
ANALYSIS: (write this up on a separate piece of paper)
1. Can you identify the gas using the table values?
CONCLUSION: (write this up on a separate piece of paper)
R – recall what you did in the activity
E – explain the purpose of the activity
R – what were your results
U – uncertainties and sources of error in the lab
N – new knowledge: what are some applications of what you have learned?
PROCEDURE:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
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15.
Carefully break the alka selzer tablet into two small pieces.
Add 15 ml of water to your test tube.
Place the test tube in the beaker.
Place the tablet pieces BESIDE the test tube in the beaker.
Use the electronic balance to measure the mass of: beaker + test tube + water + alka seltzer
tablet
Fill your collection jar with water and invert it in the collection tub.
Place the rubber hose into the inverted collection jar.
Drop one piece of alka selzer tablet into the test tube and quickly insert the rubber stopper
with the robber hose.
Wait until you stop producing bubbles in the collection jar.
Drop the second piece of alka selzer tablet into the test tube and stopper.
Again wait until you stop producing bubbles in the collection jar.
Move the rubber band so that it lines up with the level of water in the collection jar.
Fill the collection jar with water up to the level of the rubber band.
Measure the volume of water in the collection jar. This is the volume of gas produced.
Use the electronic balance to measure the mass of: beaker+test tube+water+contents