In the Lab
In one of the first lab activities, we took steel wool and placed it in a bunsen burner flame. What appeared to happen to the mass of the steel wool?
Increase, Decrease, No change
Increased (due to oxygen reacting and combining with the steel wool)
Solids are typically more dense than liquids(with the exception of ice and water) and liquids are more dense than gases. What does that mean about the spacing of solid particles compared to gas particles?
solid particles are a lot closer packed together. Gas particles are spread apart.
This is the measure of how much matter is in a substance.
Mass
What is the name of the error that occurs when you do not look at a measuring instrument directly, but instead are off to the side, above, or below the instrument you are trying to measure
Parallax
Convert 35 kg to g
35000 g
A substance in the lab is placed in a graduated cylinder. The original reading of the graduated cylinder is 24.6 mL. The final reading is 32.4 mL. What is the volume of the substance you added to the graduated cylinder?
7.8 mL or 7.8 cm3
Determine the volume of a substance with a mass of 25 g and a density of 2.5 g/cm3
10 cm3 or 10mL
This states that in any process, mass cannot be gained or lost in a system. In other words, mass cannot be created or destroyed.
Law of Conservation of Mass
In every measurement we take, there should be how many estimated digits?
1 and only 1
Convert 2.5 micrometers to centimeters
0.00025 cm
Will vegetable oil sink, float, or mix with ethyl alcohol?
Density of vegetable oil = 0.93 g/mL
Density of ethyl alcohol = 0.789 g/mL
Sink
If given a graph of mass and volume of a substance, what about the graph tells us the density of the substance
The slope of the line
__________ means a measurement is close to the correct value and _________ means the measurement is repeatable.
Accuracy, Precision
You have a substance you find to be 13.5 cm3. You place this substance in a graduated cylinder which has an initial water volume of 28.2 mL. What will the final water level reading be after placing the substance in the graduated cylinder?
41.7 mL
Convert 5 x 10-20 MegaBaughmans to picoBaughmans
0.05 picoBaughmans
You have two separate samples of aluminum metal. The first sample is 50 g and the second is 100 g. We can be sure that __________ is unchanged about these samples but __________ is doubled(besides mass).
density, volume
Remember, if it is the same substance, the ratio of mass to volume doesn't change. That means if mass doubles, volume must also double but when we divide these two numbers we end up with the same density still!
Calculate the mass if given a substance with a volume of 20 cc and a density of 4 g/mL
80 g
This is the name given to units which are a combination of base units. Some examples include Joules, cm3, L, Newton, Watts, and Molar.
Derived units
Take a proper reading of this graduated cylinder.
http://www.doe.mass.edu/mcas/images/2010/177347_1790_stem_01.png
36.4, 36.5, 36.6, 36.7, 36.8 would all be acceptable with units of mL
Convert 15.5 km to miles
9.63 miles
You are in the lab and given a rectangular cylinder with the following dimensions:
4 cm x 3 cm x 12 cm.
You find the mass of the cylinder to be 140 g.
a) Determine the density of the cylinder?
b) Will the cylinder sink or float in water?
a) 0.972 g/mL or 0.972 g/cm3
b) floats (more dense than sinks, less dense floats)
You start with a graduated cylinder with 15.0 mL of water. You find the mass of a metal to be 12.0 g. You place the metal into the graduated cylinder and the volume raises to to 16.5 mL. What is the density of this metal?
8 g/mL
What is the name of the bubble that forms in a graduated cylinder which you should get eye-level with the bottom of in order to read properly?
meniscus
What is the proper measurement of the paperclip in this picture?
2.30, 2.31, 2.32, 2.33, 2.34, 2.35 would all be acceptable with the units of cm
Convert 1,296,000 seconds to days
15 days