Driver's Ed

Determine whether each quantity is a measured value or an exact value.

2 cups of milk double_arrowMeasured 2 avocados double_arrowExact 144 grams of sugar double_arrowMeasured 1 ft = 12 in double_arrowExact 3 teacups double_arrowExact 18 meters double_arrowMeasured

A series of measurements in the lab led to an experimental result of 32.9 mL, with a calculated standard deviation of 0.3 mL. What is the standard way to report this result?

32.9 ± 0.3 mL

Identify the following errors as systematic or random.

A thermometer is placed such that the bulb makes poor contact with the measured substance, giving erratic temperature readings.double_arrowRandom A micropipet is improperly calibrated, and the balance dispensed is always smaller than expected. double_arrowSystematic The last digit on a pH meter fluctuates up and down as a measurement is taken. double_arrowRandom A few drops of water are on a balance pan, causing the mass output on the balance to be high each time it is used. double_arrowSystematic

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 from this sample after the experiment is complete?

Check and see if anyone else can use the chemical. If not, discard in the proper waste container.

If you drop or break glassware in lab, first

If you drop or break glassware in lab, first get thick gloves or dustpan . Then, carefully collect all the broken glassware. Finally, place all that material into the broken glass container.

What needs to be included in the label for each axis of a graph?

Name of quantity displayed on axis Units of quantity displayed on axis

Which steps are necessary for cleaning a spill involving broken glass?

Stop the spread of the spill. Soak up any spilled liquid with absorbent material. Pick up large pieces of glass with gloved hands.

Under what conditions should a student inform the instructor of a lab injury?

The instructor must be informed of all laboratory injuries.

Suppose that two students perform a titration experiment multiple times, resulting in the average concentrations reported here. Student A 0.125 ± 0.008 MStudent B0.12 ± 0.03 M

The more precise work was done by Student A because that student's data has a smaller standard deviation.

Identify the recommended practices when putting a tip on a micropipette.

Use the tip size designed for the micropipette size in use. Gently push the micropipette into the tip and tap lightly to load the tip.

Determine the safest option in the lab if you need your vision to be corrected.

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

Determine when you should remove your goggles in the lab room.

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

percent error

refer to picture

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

Determine the number of significant figures in each measurement. Then, choose the representation of the number where x is in place of the estimated digit from the measurement.

14.8 3 sig figs, 14.x 6200 2 sig figs 6x00 1.000 g/ml 4 sig figs, 1.00x

When drawing up liquid into a micropipette, put the tip in the liquid at a 90 degree angle, push the plunger to the first point of resistance, and then release the plunger. When dispensing that liquid from the micropipette, hold the micropipette at a 45 degree angle in the desired container and push the plunger to the second point of resistance. Hold down the plunger until dispensing is done.

90, first, release, 45,second, hold down

Using the letters on the image, identify each component of the liquid waste set-up.

A double_arrowFunnel B double_arrowPrimary container C double_arrowWaste label D double_arrowSecondary container

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.

Changing gloves often will minimize the spread of chemicals

How do you determine the last digit in any measured number?

Estimate one digit past the smallest precisely known digit or marking.

Which types of signs are posted to convey information about chemical storage?

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

What information is necessary to review in order to be considered familiar with the Safety Data Sheet (SDS) of a substance?

Identification and description of substance Hazard warnings Personal protection and first aid recommedations Handling, storage, and reactivity information

Review the Safety Data Sheet (SDS) (click the SDS icon below) for potassium hydroxide, then identify the best course of action for each type of chemical exposure.

In case of eye contact double_arrowRinse with water for 15 minutes. If swallowed double_arrowRinse mouth with water. If inhaled double_arrowMove person to fresh air. In case of skin contact double_arrowTake off any contaminated clothing and rinse thoroughly

What information is needed in order to be prepared for an emergency?

Location of all exits Contact information for emergency personnel Location of lab phone and first aid kit Understanding of where to go should an emergency occur

nfpa diamond

Red=Flammability, Yellow=Reactivity, Blue=Health, White=Special Precautions, 1 is lowest hazard, 4 is extremely hazardous

What should you do every time before you leave the lab?

Remove your gloves. Wash your hands. Remove your labcoat, if you are wearing one.

Read each statement regarding food and beverages in the lab and determine if each is true or false.

Tobacco products of all kinds are prohibited in lab. double_arrowTrue Beverages are allowed in lab as long as they are in containers with lids. double_arrowFalse Food items should not be brought into the lab. double_arrowTrue Chewing gum is okay in the lab as long as you don't blow bubbles. double_arrowFalse

Determine whether each practice is recommended to keep a micropipette clean and functioning properly.

Use a new tip any time you change solutions. double_arrowRecommended Save tips after removal to reuse them later. double_arrowNot recommended Place the micropipette on a rack after using it. double_arrowRecommended Turn the micropipette upside down after loading with liquid. double_arrowNot recommended Place the micropipette on the bench between uses. double_arrowNot recommended

In lab, you may need to evaluate the odor or smell of a chemical. What is the best way to smell a chemical sample?

Use your hand to gently waft the smell toward you.

The purpose of the best-fit line on an experimental scatterplot is to identify any linear trend in scattered data. The best-fit line allows us to predict behavior between measured data using its slope.

identify any linear trend in scattered data, predict behavior between measured data using its slope.

Identify the section in which each type of information can be found on a Safety Data Sheet.

possible dangers and health effects double_arrowHazards Identification recommended personal protective equipment (PPE) double_arrowExposure Controls/Personal Protection recommendations in case of accidental contact with the chemical double_arrowFirst Aid Measures chemical name and formula double_arrowIdentification incompatibility or reactivity with other chemicals double_arrowHandling and Storage

Consider the given graph of an object's mass and volume. What is the density of the object, in g/mL?

read slope

What information does not need to be included a chemical waste label?

A description of the experiment the chemicals were used for

What are the best practices for safely handling waste in the lab?

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

When inputting a formula into Excel or other spreadsheet software, what components are required for the formula to function properly?

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

Determine when to put on disposable gloves for work in the lab.

Before handling any glassware or chemicals for the experiment

What is generally the best approach when liquid from a large reagent bottle is needed in an experiment?

Pour some of the reagent from the bottle into a beaker, then use as needed in the procedure.

Which line is the best-fit line to represent the black data points?

Red Line

When should you start a new chemical waste container in the lab?

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

What is the last step of any spill cleanup procedure?

Wipe down the affected area with detergent and water.

Determine the best way to deal with each of the following items that may dangle into the way during lab work.

flowy sleeves double_arrowTie back or secure loose bracelets double_arrowRemove long earrings double_arrowRemove long necklaces double_arrowRemove long hair double_arrowTie back or secure

Gas cylinder

for gases under pressure

be able to perform average mass

g

Systematic error is caused by

improper use of a measuring device random fluctuations in a measuring device

Determine where to dispose of each type of waste.

syringe tips double_arrowSharps container unused solid reagent double_arrowSolid waste containerbroken flaskdouble_arrowBox lined with puncture resistant bag titrant solution double_arrowNalgene bottle with cap

Eyewash station

used to rinse the eyes when they have contacted a chemical

safety shower

used to rinse the skin or clothing of a hazardous chemical

atch each lab incident to the item of PPE that will protect you from it. Each item of PPE will only be used once.

While picking up a buret, an unknown solution left by a previous solution drips onto your hand. double_arrowGloves While checking on a stirring solution, the solution splashes up towards your face. double_arrowGogglesWhile pulling an empty beaker off the shelf at the beginning of lab, it slips out of your hand onto the floor. double_arrowClosed-toe shoes While transferring a solution from a flask to a beaker, the solution accidentally spills down the front of the lab bench. double_arrowLab coat

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

Your lab partner

1. Surround the area with absorbent material, then cover the spill. 2. Scoop up the material and place in a plastic bag. 3. Place the bagged waste in a solid waste container. 4. Wipe down the area with detergent and water

absorbent material, plastic bag, solid waste container, detergent and water

When describing the uncertainty of a measurement, the term accuracy refers to the closeness between a measurement and its accepted value, whereas the term precision refers to the closeness among a set of measurements.

accuracy, precision

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