gen chem final

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"

(3) a. Hazard signs such as "Flammable," "Oxidizer," and "Corrosive" b. National Fire Protection Association (NFPA) diamond c. Gas Cylinder sign

Perform the calculation, rounding your answer to the proper number of significant figures. 0.35200 ÷ 2.740 = Type answer:

0.1285

Identify the description that applies to the substance represented by each NFPA diamond. 1. diamond with OX in white square 2. diamond with a 2 in blue, 3 in red, and 0 in yellow square 3. diamond with a 3 in blue, 2 in yellow, and 0 in red square 4. diamond with COR written in white square

1. oxidizer, not flammable 2. stable, has health risks but no special hazards 3. moderately unstable or reactive 4. flash point below room temperature

Determine the relative order of the metric prefixes of kilo-, micro-, centi-, and milli-. For the same base unit, _____ is less than _____, which is less than ______, which is less than ______.

For the same base unit, micro- is less than milli-, which is less than centi-, which is less than kilo-.

Determine the safest option in the lab if you need your vision to be corrected. Select one: a. 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 b. Wear safety goggles while working and switch to corrective glasses when you need to read something c. Wear your corrective glasses or lenses as normal for the whole experiment d. Wear safety goggles without any corrective lenses for the whole experiment

a. 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

Identify the common indicators that a chemical reaction has occurred. Select one or more:

Precipitate being formed Bubbles being produced A color change A change in temperature

What visible signs indicate a precipitation reaction when two solutions are mixed?

Solid setting out in the test tube A hazy or cloudy appearance

Suppose the reaction of chlorine water with a halide solution produces a halogen X2, and a salt, NaCl. In the presence of mineral oil, the halogen will dissolve in the oil and the salt will remain in the aqueous layer

Suppose the reaction of chlorine water with a halide solution produces a halogen X2, and a salt, NaCl. In the presence of mineral oil, the halogen will dissolve in the oil and the salt will remain in the aqueous layer

Determine when you should remove your goggles in the lab room. Select one: a. When everyone in the room is done handling any chemicals or glassware b. When you have finished cleaning up your chemicals and glassware c. Whenever you need to lean in close to get a volume reading d. Whenever your goggles become foggy or uncomfortable

a. When everyone in the room is done handling any chemicals or glassware

For each reaction, determine whether it is an example of combustion or not.

To identify a combustion reaction, O2 needs to be a reactant on the left side of the reaction arrow.

To identify a halide, you can react with chlorine water in the presence of mineral oil. If the unknown halide is a stronger reducing agent than chlorine, the halide will be oxidized to its elemental form which would change the color of the mineral oil layer

To identify a halide, you can react with chlorine water in the presence of mineral oil. If the unknown halide is a stronger reducing agent than chlorine, the halide will be oxidized to its elemental form which would change the color of the mineral oil layer

What information does not need to be included a chemical waste label? Select one: a. A description of the experiment the chemicals were used for b. Names of the chemical compounds present in the container c. Relative amounts of chemical compounds in the container d. The date the waste container was filled completely

a. a description of the experiment the chemicals were used for

What is the main precaution to take if a Gas Cylinder sign is present in the lab? Select one: a. Visually check that the gas cylinder is restrained but keep a safe distance from it. b. Open the valve on the gas cylinder periodically to release pressure. c. Test out the regulator on the gas cylinder to make sure it is working properly. d. Remove the strap from around the gas cylinder to use it in the lab.

a. Visually check that the gas cylinder is restrained but keep a safe distance from it.

Which chemical waste situation should always be supervised or performed by an instructor? Note that you still may need to alert your instructor about the described incident, even if you clean it up yourself. Select one: a. Cleaning up a broken mercury thermometer b. Cleaning up solutions from a titration experiment c. Cleaning up solid residue from a precipitation experiment d. Cleaning up a broken beaker containing sodium chloride solution

a. cleaning up a broken mercury thermometer

Identify tools that are ideal for cleaning glassware. Select one or more: a. detergent and water b. brushes c. reusable cloths d. steel wool

a. detergent and water b. brushes

Identify each piece of glassware commonly found in the laboratory. a. the beaker looking thing with a curved top b. cylinder c. beaker d. tube e. skinny tube

a. erlenmeyer flask b. graduated cylinder c. beaker d. test tube e. burette

Identify the equipment best suited for extinguishing each type of fire. a. large fire on floor b. clothing fire c. small benchtop fire

a. fire extinguisher b. fire blanket c. overturned beaker

Identify the safety equipment designed to deal with each emergency listed: a. large fire on the benchtop b. chemicals on clothes c. cuts or minor burns d. fire on a person e. chemicals in eyes

a. fire extinguisher b. safety shower c. first aid kit d. fire blanket e. eyewash station

Identify the calculations possible using only 28.02 g/mol as a conversion factor. Select one or more: a. Calculate the grams of N2N2 in 5.03×10205.03×1020 moles of nitrogen molecules b. Calculate the moles of N2N2 molecules in 3.94 grams of nitrogen c. Calculate the moles of N2N2 molecules in 4.73 liters of nitrogen gas d. Calculate the grams of N2N2 in 10.58 liters of nitrogen gas

b. Calculate the moles of N2N2 molecules in 3.94 grams of nitrogen a. Calculate the grams of N2N2 in 5.03×10205.03×1020 moles of nitrogen molecules

Identify the precautions to take with exits in the lab. Select one or more: a. Make sure lab windows are always open. b. Locate the exits prior to the start of lab. c. Keep the exit door locked at all times. d. Do not block a door with an EXIT sign.

b. Locate the exits prior to the start of lab. d. Do not block a door with an EXIT sign.

In case of accidental contact with chemicals, how long should the eyes be flushed at the eyewash station? Select one: a. 5 minutes b. Until the irritation is gone c. 15 minutes d. 30 minutes

c. 15 minutes

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 should be alerted only if the lab injury appears different from injuries the student has experienced previously. c. The instructor must be informed of all laboratory injuries. d. The instructor should be alerted only if the injury involves broken skin.

c. The instructor must be informed of all lab injuries.

When should you start a new chemical waste container in the lab? Select one: a. When the contents of the current container completely fill the container to the brim b. When you accidentally spill chemicals down the side of the current container c. When the contents of the current container are a couple inches below the brim of the container d. When you need to dispose of another chemical that is compatible with chemicals in the current container

c. When the contents of the current container are a couple inches below the brim of the container

Determine when to put on disposable gloves for work in the lab. Select one: a. before entering the laboratory room b. after setting up all the glassware but before handling chemicals c. after cleaning all the glassware for the experiment d. before handling any glassware or chemicals for the experiment

d. Before handling any glassware or chemicals for the experiment

What should you do every time before you leave the lab? Select one or more: a. Turn off the lights. b. Wash your hands. c. Remove your lab coat, if you are wearing one. d. Remove your gloves.

d. Remove your gloves. b. Wash your hands. c. Remove your lab coat, if you are wearing one.

Identify each lab safety sign pictured. (diamond w squares inside, eye with plus next to it, guy running out with an arrow, shower, and red square with black cylinder inside)

diamond w squares inside is the NFPA diamond eye with the plus sign is eye wash station guy running out is exit shower is safety shower red square with black cylinder inside is gas cylinder

All lab participants must remain prepared to use safety equipment in case of emergency. Identify the components of effective preparation. Select one or more: a. Practicing with safety equipment before the start of each lab session b. Being familiar with how safety equipment is used c. Understanding where the safety equipment is located d. Researching alternatives to the safety equipment available in lab e. Knowing what safety equipment is available

e. Knowing what safety equipment is available c. Understanding where the safety equipment is located b. Being familiar with how safety equipment is used

Suppose you measure out 2.45 g of a metal, which corresponds to 0.0908 mol of the metal, and react with enough hydrochloric acid to produce 12.11 g of the metal chloride. Based on the data, what is the formula for the chloride you produced?

explanation: 1. mass of H2O=12.11 g−2.45 g=9.66 g Cl 2. 9.66 g Cl/molar mass of Cl=0.272 mol Cl 3. 0.272 mol Cl/O.0908 mol M = 3 mol Cl : 1 mol M So, answer is MCl3

Match each lab incident to the item of PPE that will protect you from it. Each item of PPE will only be used once. a. While checking on a stirring solution, the solution splashes up towards your face. b. While picking up a buret, an unknown solution left by a previous solution drips onto your hand. c. While pulling an empty beaker off the shelf at the beginning of lab, it slips out of your hand onto the floor. d. While transferring a solution from a flask to a beaker, the solution accidentally spills down the front of the lab bench.

a. goggles b. gloves c. closed-toe shoes d. lab coat

Choose the most appropriate task for each pictured piece of glassware. a. graduated cylinder b. beaker c. erlenmeyer flask

a. measuring out volume of a liquid b. pouring an approximate volume of liquid into a burette c. containing a stirred reaction mixture

Determine the best way to deal with each of the following items that may dangle into the way during lab work. a. loose bracelets b. long hair c. flow sleeves d. long earrings e. long necklaces

a. remove b. tie back or secure c. tie back or secure d. remove e. remove

When inputting a formula into Excel or other spreadsheet software, what components are required for the formula to function properly? Select one or more: a. A named function (i.e. SUM) in the formula b. An equal sign at the beginning of the formula c. A reference to at least one other cell in the spreadsheet d. Closing parentheses for any opening parentheses

b. An equal sign at the beginning of the formula d. Closing parentheses for any opening parentheses

A football field is 120 yards by 53.333 yards. What is the area of the football field in acres if 1 acre=43560 ft2? Use correct significant figures when answering this question. Type answer:

1.3 Explanation: distance in feet=distance in yards×3 ft/1yd measured side in ft=120 yds×3 ft/1 yd= 360 ft other measured side in ft=53.333 yds×3 ft/1 yd=159.9999 ft Then calculate the area of the field in square feet. area in ft^2=measured side in ft×other measured side area in ft2=360 ft×159.9999 ft=57596.4 ft^2 Finally, convert area in square feet to acres. area in ft^2 = 1 acre/43560 ft^2 so, 57596.4 ft^2× 1 acre/43560 ft^2=1.32223 acres= 1.3 acres (using sig figs of 2 from the 120 yards in the beginning)

What is the correct way to report the length of the rectangle in centimeters? (RULER)

15.60 cm

Knowing that one day is 24 hours and one hour is 60 minutes, how many minutes are in 2.2 days? Type answer:

3200

Knowing that one day is 24 hours, how many days is 97.6 hours?

4.07

What is the correct reading for the graduated cylinder in the close-up? Make sure to report your reading with the appropriate significant figures. GRADUATED CYLINDER

40.5 mL

Determine whether each observation generally corresponds to a physical change or a chemical change.

A chemical change involves the creation of at least one new substance whereas physical changes are alterations to the starting substance. The formation of bubbles or a precipitate clearly indicates that a new substance has been created and a chemical reaction has occurred. An inherent color change or change in temperature indicates changes to the chemical makeup of the substance, even if the new substances are not visible. Note that external changes to color, such as applying paint, or to temperature, such as heating on a hot plate, are physical changes. These external changes are alterations to the starting substance. A phase change, such as melting or boiling, or a solid being dissolved are signs of physical changes, not chemical reactions. In both cases, the original substance is still present, just in a different form.

Which signs are typically posted in areas of active lab work? Select one or more: a. Personal protective equipment (PPE) sign b. Chemical storage signs c. Sign prohibiting food and drink d. Safety equipment signs

All !!!!

What parts are present in every chemical equation? Select one or more:

At least one reactant At least one product An arrow

Changing gloves often will minimize the spread of chemicals. To properly remove gloves, first, ___________, and then, ___________. Then insert a _________ between the interior edge of the second glove and the skin, and remove the second glove.

Changing gloves often will minimize the spread of chemicals. To properly remove gloves, first, grasp the exterior of one glove with a gloved hand, and then, peel off the first glove. Then insert a bare finger between the interior edge of the second glove and the skin, and remove the second glove.

In the context of a balanced chemical equation, a subscript is a number to the lower right of an element or ion within formula and it applies to only the part of the formula it follows. A coefficient is a number to the left of a formula and it applies to the entire formula it precedes. Only coefficients should be added or changed when balancing chemical equations.

In the context of a balanced chemical equation, a subscript is a number to the lower right of an element or ion within formula and it applies to only the part of the formula it follows. A coefficient is a number to the left of a formula and it applies to the entire formula it precedes. Only coefficients should be added or changed when balancing chemical equations.

What should you do every time you are about to heat glassware on a hot plate?

Inspect the hot plate for frayed cords Check that there are no cracks in the glassware Ensure that the glassware is designed for heating

Labware and Math Review

Labware and Math Review

In the reaction Mg+2HCl -> MgCl2+H2

Mg is oxidized and H is reduced

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 ___________.

Move to the safety shower if you spill hazardous chemicals on your skin or clothing. Stand under the shower and pull the lever. Remove clothing and continue flushing the area for 15 minutes.

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 ________.

To measure out a volume of liquid, start by choosing the appropriate graduated cylinder and moving the bumper to the top of the graduated cylinder to protect it from breakage. Then, pour the liquid into the graduated cylinder until the bottom of the meniscus aligns with the desired volume marking when you look at the graduated cylinder from eye level.

When heating a solution to boiling on a hot plate, start by ________. Then, turn the heat to _______ to start. If necessary, _________ after waiting about ten minutes without seeing boiling.

When heating a solution to boiling on a hot plate, start by starting and stabilizing the stir function. Then, turn the heat to a medium heat setting to start. If necessary, turn up the heat setting after waiting about ten minutes without seeing boiling.

When using the Tare function on a balance, start by, ______. Then, _______ to cancel out the mass. Finally, ________ and record the mass of your sample.

When using the Tare function on a balance, start by placing the glassware on the balance. Then, press the Tare/Zero button to cancel out that mass. Finally, add your sample to the glassware and record the mass of your sample.

Predict the products of hydrochloric acid reacting with zinc metal. Select one or more:

ZnCl2 H2

Suppose you mix NaCl and AgNO3 solution according to the given equation...

a precipitate should form

What are the best practices for safely handling waste in the lab? Select one or more: a. Always wear appropriate Personal Protective Equipment. b. Place any paper towels from the clean-up in the trash. c. Remove gloves for better manipulation of the waste containers. d. Check labels or instructions before any disposal.

a. Always wear appropriate Personal Protective Equipment. d. Check labels or instructions before any disposal.

When is the best time to clean glassware during the lab session? Select one: a. As soon as practical after use b. Once there is a sink full of items c. All at once at the end of the session d. Whenever you run out of clean glassware

a. As soon as practical after use

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. Alert your TA or instructor about any issues with the balance. c. Leave a note when you have tared a balance for your glassware. d. Place samples directly onto the balance.

a. Brush off any chemical dust around the balance after each use. b. Alert your TA or instructor about any issues with the balance.

Which procedure cannot be performed on a hot plate, requiring a Bunsen burner instead? Select one: a. Heating a crucible to remove water from a hydrate b. Heating an isolated solid to dry it c. Heating water to boiling for a water bath d. Heating a solvent to help the solute dissolve

a. Heating a crucible to remove water from a hydrate

It is often helpful to remember the acronym PASS when using a fire extinguisher. Fill in the word that corresponds with each letter to complete the steps needed for operation of this device. P: ______ the pin A: ______ the nozzle at the base of the fire S: _______ the lever slowly S: _______ the spray from side to side over the fire

pull the pin aim the nozzle squeeze the lever sweep the spray from side to side

Which of the following forms precipitates with most halogens?

silver nitrate

Using the letters on the image, identify each component of the liquid waste set-up. (image of the waste inside a big container)

the top is the funnel, the middle is the primary container, the label is the waste label, the huge container is the secondary container

Which is NOT a good source of information about the hazards that affect waste disposal in a chemistry lab?

your lab partner