CHM 108 Lab Midterm
What is the density of a BaCl2BaClX2 solution, in g/mL, if a 5.00 mL sample has a mass of 5.18 g?
1.036 g/mL
A block has a mass of 4.465 g and a volume of 143.2 cm^3. Calculate the density in g/cm^3.
0.031 g/cm^3
Fill in the words to complete the step in liquid spill cleanup. Surround the area with _______, then cover the spill.
Absorbent Material
Soluble
Capable of being dissolved.
A precipitate is formed from two solutions.
Chemical change
Determine whether the observation generally corresponds to a physical change or a chemical change. A solution heats up upon mixing with another.
Chemical change
Determine whether the observation generally corresponds to a physical change or a chemical change. Bubbles are produced upon mixing two solutions.
Chemical change
Determine whether the property is a physical property of a chemical property. Flammability
Chemical property
Determine whether the property is a physical property of a chemical property. Reactivity
Chemical property
A value used to describe the amount of one substance dissolved in another.
Concentration
Identify the name of the phase change corresponding to the transition. Gas to liquid
Condensation
Solid
Definite shape and volume.
Identify the image.
Exit
Identify the image.
Eyewash Station
Identify the safety equipment designed to deal with this emergency. Chemicals in eyes
Eyewash station
Fire on a person
Fire Blanket
Identify the safety equipment designed to deal with this emergency. Large fire on the benchtop
Fire extinguisher
Identify the safety equipment designed to deal with this emergency. Cuts or minor burns
First Aid Kit
Identify the name of the phase change corresponding to the transition. Liquid to solid
Freezing
Identify the image.
Gas Cylinder
Match the lab incident to the item of PPE that will protect you from it. While picking up a buret, an unknown solution left by a previous solution drips onto your hand.
Gloves
Match the lab incident to the item of PPE that will protect you from it. While transferring a solution from a flask to a beaker, the solution accidentally spills down the front of the lab bench.
Lab coat
Immiscible Liquid
Liquids which do not mix.
Identify the image.
NFPA Diamond Red = Fire Hazard Blue = Health Hazard Yellow = Reactivity White = Specific Hazard
Determine where to dispose of titrant solution.
Nalgene bottle with cap
Fill in the words to complete the step in liquid spill cleanup. Scoop up the material and place in a _____.
Plastic Bag
Determine the best way to deal with the following item that may dangle into the way during lab work. Long earrings
Remove
Determine where to dispose of syringe tips.
Sharps container
A liquid consisting of one substance dissolved in another.
Solution
A liquid that dissolves another substance.
Solvent
Determine whether the property described applies to volumetric or graduated glassware. Designed to measure one specific volume of liquid.
Volumetric
A student removes a chemical sample from a reagent bottle to be used in an experiment. What should he do with any excess chemical remaining form this sample after the experiment is complete? a. Clean a spatula thoroughly, then use it to add the chemical back into the reagent bottle. b. Check and see if anyone else can use the chemical. If not, discard in the proper waste container. c. Discard the chemical down the sink under running water. d. Conduct a second trial of the experiment with the excess chemical.
b. Check and see if anyone else can use the chemical. If not, discard in the proper waste container.
In general, which characteristics are necessary for a location to be suitable for chemical storage? a. Poorly-ventilated b. Cool c. Warm d. Dark e. Dry
b. Cool d. Dark e. Dry
What needs to be included in the label for each axis of a graph? Select one or more: a. Relationship to quantity displayed on other axis. b. Name of quantity displayed on axis. c. Description of how measurement was made. d. Units of quantity displayed on axis.
b. Name of quantity displayed on axis. d. Units of quantity displayed on axis.
Fill in the words to complete the step in liquid spill cleanup. Wipe down the area with _____.
Detergent and Water
Suppose you place 3.31 mL of a substance into a graduated cylinder. The graduated cylinder has a mass of 12.55 g when empty and a mass of 15.57 g after adding the substance. What is the density of the substance (in g/mL)?
0.91 g/mL
Identify the name of the phase change corresponding to the transition. Solid to liquid
Melting
Identify the element as metal, non-metal, or metalloid. Fluorine
Non-metal
Identify the element as metal, non-metal, or metalloid. Phosphorus
Non-metal
Determine whether the property is a physical property of a chemical property. Solubility
Physical property
Identify the image.
Safety Shower
Identify the safety equipment designed to deal with this emergency. Chemicals on clothes
Safety Shower
Fill in the words to complete the step in liquid spill cleanup. Place the bagged waste in a ______.
Solid Waste Container
Sublimation
Solid to gas.
Determine where to dispose of unused solid reagent.
Solid waste container.
A chemical that is dissolved.
Solute
Determine the item of personal protective equipment (PPE) you will likely use in a general chemistry lab. Select one or more: a. Lab coat b. Hear muffs c. Gloves d. Face Mask e. Face Shield f. Goggles
a. Lab coat c. Gloves f. Goggles
Changing gloves often will minimize the spread of chemicals. To properly remove gloves, first, _____, and then, _____. Then insert _____ between the interior edge of the second glove and the skin, and remove the second glove.
grasp the exterior of one glove with a gloved hand; peel off the first glove; a bare finger
Suppose you are titrating an acid of unknown concentration with a standardized base. At the beginning of the titration, you read the base titrant volume as 2.32 mL. After running the titration and reaching the endpoint, you read the base titrant volume as 22.89 mL. What volume, in mL, of base was required for the titration?
20.57 mL
Determine whether the observation generally corresponds to a physical change or a chemical change. The color of a substance changes over time.
Chemical change
Identify the element as metal, non-metal, or metalloid. Manganese
Metal
Identify the element as metal, non-metal, or metalloid. Silver
Metal
Identify the element as metal, non-metal, or metalloid. Tin
Metal
Identify the element as metal, non-metal, or metalloid. Titanium
Metal
Identify the element as metal, non-metal, or metalloid. Germanium
Metalloid
Identify the element as metal, non-metal, or metalloid. Silicon
Metalloid
Identify the element as metal, non-metal, or metalloid. Sulfur
Non-metal
Determine whether the observation generally corresponds to a physical change or a chemical change. A liquid freezes into a solid.
Physical change
Determine whether the observation generally corresponds to a physical change or a chemical change. A solid dissolves into water.
Physical change
Determine whether the property is a physical property of a chemical property. Color
Physical property
Determine whether the property is a physical property of a chemical property. Density
Physical property
Determine whether the property is a physical property of a chemical property. Melting point
Physical property
Determine the best way to deal with the following item that may dangle into the way during lab work. Long necklaces
Remove
Determine the best way to deal with the following item that may dangle into the way during lab work. Loose bracelets
Remove
What is the relationship between energy and wavelength?
Short wavelength and high frequency = More energy Long wavelengths and low frequency = Less energy
What information is necessary to review in order to be considered familiar with the Safety Data Sheet (SDS) of a substance? Select one or more: a. Literature examples of use of the substance. b. Handling, storage, and reactivity information. c. Personal protection and first aid recommendations. d. Identification and description of substances. e. Hazard warnings.
b. Handling, storage, and reactivity information. c. Personal protection and first aid recommendations. d. Identification and description of substances. e. Hazard warnings.
Under what conditions should a student inform the instructor of a lab injury? Select one: a. The instructor needs to be alerted only if he or she needs to call 911. b. The instructor must be informed of all laboratory injuries. c. The instructor should be alerted only if the injury involves broken skin. d. The instructor should be alerted only if the lab injury appears different from injuries the student has experienced previously.
b. The instructor must be informed of all laboratory injuries.
Determine when to put on disposable gloves for work in the lab. Select one: a. Before entering the laboratory room. b. After cleaning all the glassware for the experiment. c. After setting up all the glassware, but before handling chemicals. d. Before handling any glassware or chemicals for the experiment.
d. Before handling any glassware or chemicals for the experiment.
In the climate change experiment, what is the role of the dry ice? Select one: a. Cooling down the beakers before the experiment. b. Removing water vapor from the air before the experiment. c. Calibration of the temperature probes to a known temperature. d. Generation of carbon dioxide gas for the experiment.
d. Generation of carbon dioxide gas for the experiment.
Which gases can act as a greenhouse gas? Select one or more: a. Oxygen b. Nitrogen c. Argon d. Water vapor e. Methane f. Carbon dioxide
d. Water vapor e. Methane f. Carbon dioxide
Determine when you should remove your goggles in the lab room. Select one: a. Whenever your googles become foggy or uncomfortable. b. Whenever you need to lean in close to get a volume reading. c. When you have finished cleaning up your chemicals and glassware. d. When everyone in the room is done handling any chemicals or glassware.
d. When everyone in the room is done handling any chemicals or glassware.
When using the Tare function on a balance, start by _____. Then, _____ to cancel out that mass. Finally, _____ and record the mass
placing the glassware on the balance; press the Tare/Zero button; add your sample to the glassware
To measure out a volume of liquid, start by choosing the appropriate graduated cylinder and moving the bumper to the ___ of the graduated cylinder to protect it from breakage. Then, pour the liquid into the graduated cylinder until the _____ of the meniscus aligns with the desired volume marking when you look at the graduated cylinder from _____.
top; bottom; eye level
Determine the best way to deal with the following item that may dangle into the way during lab work. Flowy sleeves
Tie back or secure
Determine the best way to deal with the following item that may dangle into the way during lab work. Long hair
Tie back or secure
Suppose you mix two solutions into a test tube and the test tube becomes hot. This is _____ because _____.
a sign of a chemical reaction; chemical changes can release heat
Choose the best graduated cylinder to this measurement in a single use: 5.75 mL of a sucrose solution a. A 10 mL graduated cylinder with markings every 0.1 mL. b. A 25 mL graduated cylinder with markings every 1 mL. c. A 50 mL graduated cylinder with markings every 10 mL.
a. A 10 mL graduated cylinder with markings every 0.1 mL.
What are the best practices for safely handling waste in the lab? a. Always wear appropriate Personal Protective Equipment. b. Check labels or instructions before disposal. c. Remove gloves for better manipulation of the waste containers. d. Place any paper towels from the clean-up in the trash.
a. Always wear appropriate Personal Protective Equipment. b. Check labels or instructions before disposal.
The greenhouse effect is a natural _____ due to energy from _____ that reaches the earth's surface and is trapped by certain gases _____.
increase in temperature; the sun; in the atmosphere
Magnesium reacts with oxygen in the air when _____. Unlike other reactions, you should not _____ this reaction.
lit with a Bunsen burner; look directly at
Suppose you mix a solid into water and not all of it dissolves. This is _____ because _____.
not a sign of a chemical reaction; the undissolved solid is not a new substance
Move to the safety shower if you spill hazardous chemicals on your _____. Stand under the shower and _____ the lever. Remove clothing and continue flushing the area for _____.
skin or clothing; pull; 15 minutes
In the climate change experiment, a graph is used to study the greenhouse effect. The x-axis of the graph should correspond to _____ and the y-axis should correspond to _____.
time; temperature
Liquid
A state of matter that has no definite shape but has a definite volume.
Determine where to dispose of a broken flask.
Box lined with puncture resistant bag.
Match the lab incident to the item of PPE that will protect you from it. While pulling an empty beaker off the shelf at the beginning of lab, it slips out of your hand onto the floor.
Closed-toe shoes
Identify the name of the phase change corresponding to the transition. Gas to solid
Deposition
Match the lab incident to the item of PPE that will protect you from it. While checking on a stirring solution, the solution splashes up towards your face.
Goggles
Determine whether the property described applies to volumetric or graduated glassware. Capable of measuring a range of volumes of liquid.
Graduated
Insoluble
Incapable of being dissolved.
Identify the name of the phase change corresponding to the transition. Solid to gas
Sublimation
Miscible Mixture
Two liquids that combine in any ratio to form a homogeneous solution.
Identify the name of the phase change corresponding to the transition. Liquid to gas
Vaporization
Determine whether the property described applies to volumetric or graduated glassware. Used for applications in which great accuracy is needed.
Volumetric
What greenhouse gases absorb thermal infrared radiation?
Water vapor Carbon Dioxide Methane Trace gases in atmosphere
When an alarm sounds in the laboratory, it is important to respond _____ and remain _____. Listen for any other instructions, turn off any _____ in use, and be prepared to leave immediately.
calmly; quiet; equipment
Choose the best graduated cylinder to this measurement in a single use: 18.5 mL of a NaCl solution a. A 10 mL graduated cylinder with markings every 0.1 mL. b. A 25 mL graduated cylinder with markings every 1 mL. c. A 50 mL graduated cylinder with markings every 10 mL.
b. A 25 mL graduated cylinder with markings every 1 mL.
Identify the observations that indicate an added solute is insoluble in water. a. A clear line appear between the added liquid and water after mixing and allowing to settle. b. The addition of the solute to water causes the combination to feel warm when mixed. c. The added solid settles to the bottom after mixing and allowing to settle. d. The combination of the solute and water appears cloudy after mixing and allowing to settle. e. The solute and water appear uniformly clear after mixing and allowing to settle.
a. A clear line appear between the added liquid and water after mixing and allowing to settle. c. The added solid settles to the bottom after mixing and allowing to settle. d. The combination of the solute and water appears cloudy after mixing and allowing to settle.
What are the best practices while sharing a lab balance with other students? Select one or more: a. Brush off any chemical dust around the balance after each use. b. Place samples directly onto the balance. c. Leave a note when you have tared a balance for your glassware. d. Alert your TA or instructor about any issues with the balance.
a. Brush off any chemical dust around the balance after each use. d. Alert your TA or instructor about any issues with the balance.
Identify the common indicators that a chemical reaction has occurred. Select one or more: a. Bubbles being produced b. A solid being dissolved c. A change in temperature d. Precipitate being formed e. A color change f. A phase change
a. Bubbles being produced c. A change in temperature d. Precipitate being formed e. A color change
Which types of signs are posted to convey information about chemical storage. Select one or more: a. Hazard signs such as "Flammable," "Oxidizer," and "Corrosive" b. National Fire Protection Association (NFPA) diamond c. Gas Cylinder sign d. Exit sign e. Safety equipment signs such as "safety shower" and "eyewash station"
a. Hazard signs such as "Flammable," "Oxidizer," and "Corrosive" b. National Fire Protection Association (NFPA) diamond c. Gas Cylinder sign
Identify the precautions to take with exits in the lab. a. Locate the exits prior to the start of lab. b. Do not block a door with an EXIT sign. c. Keep the exit door locked at all times. d. Make sure lab windows are always open.
a. Locate the exits prior to the start of lab. b. Do not block a door with an EXIT sign.
Most laboratory chemical spills are cleaned up in similar manner, but acid and base spills require an extra step. What is this extra step? a. Neutralize the spill before cleaning it up. b. Tell all other lab participants to evacuate the lab as quickly as possible. c. Alert the proper authorities about the corrosive chemical waste. d. Be sure to replace the spilled acid or base.
a. Neutralize the spill before cleaning it up.
Determine the safest option in the lab if you need your vision to be corrected. Select one: a. Wear safety goggles while working and switch to corrective glasses when you need to read something. b. Wear corrective glasses or lenses under your safety goggles for the whole experiment, but always check with your TA or instructor for your school's policy. c. Wear safety goggles without any corrective lenses for the whole experiment. d. Wear your corrective glasses or lenses as normal for the whole experiment.
b. Wear corrective glasses or lenses under your safety goggles for the whole experiment, but always check with your TA or instructor for your school's policy.
A student is likely to make many observations over the course of the lab session. In general, which types of observations are necessary to record in a lab notebook? Select one or more: a. Color of the work surface in the lab. b. Length of time a substance is heated on a hot plate. c. Appearance of gas bubbles during a chemical reaction d. Mass or volume of reagents used. e. Color
b. length of time a substance is heated on a hot plate c. appearance of gas bubbles during a chemical reaction d. mass or volume of reagents used e. color or temperature change of a substance
Choose the best graduated cylinder to this measurement in a single use: 36 mL of water a. A 10 mL graduated cylinder with markings every 0.1 mL. b. A 25 mL graduated cylinder with markings every 1 mL. c. A 50 mL graduated cylinder with markings every 10 mL.
c. A 50 mL graduated cylinder with markings every 10 mL.
What information does not need to include a chemical waste label? a. Relative amounts of chemical compounds in the container. b. Names of the chemical compounds present in the container. c. A description of the experiment the chemicals were used for. d. The date the waste container was filled completely.
c. A description of the experiment the chemicals were used for.
What visible signs indicate a precipitation reaction when two solutions are mixed? Select one or more: a. Bubbling in the test tube b. A color change c. A hazy or cloudy appearance d. Solid settling out in the test tube
c. A hazy or cloudy appearance d. Solid settling out in the test tube
What practice will not help you make an accurate volume reading on a buret at the beginning of a titration? Select one: a. Read the volume with the meniscus at eye level. b. Read the volume at the bottom of the meniscus. c. Make sure that the meniscus starts at 0.00mL. d. Make sure the meniscus falls within the marked range on the buret.
c. Make sure that the meniscus starts exactly at 0.00 mL.
What is the first step for response to an emergency situation? a. Run outside the building as quickly as possible and call 911. b. Yell for help and assist with the evacuation of the lab. c. Remain calm and quiet, gather information, and assess the situation. d. Discuss the situation with the other students until everyone agrees on what to do.
c. Remain calm and quiet, gather information, and assess the situation.
The first step in the climate change involves heating two empty beakers and comparing them. What is the purpose of heating the two empty beakers in the lab? Select one: a. To make sure that the lamp works as expected for the rest of the experiment. b. To warm the beakers before adding the dry ice to help it melt. c. To ensure that the beakers receive the same amount of heat from the lamp. d. To determine the heat capacity of the beakers being used in the rest of the experiment.
c. To ensure that the beakers receive the same amount of heat from the lamp.
Which is NOT a good source of information about the hazards that affect waste disposal in a chemistry lab? a. The chemical bottle labels. b. Your instructor's directions. c. Your lab partner. d. The chemical Safety Data Sheets.
c. Your lab partner.