Lab flow Final Exam prep
How many moles of HCl are in 52.3 mLof a 1.17 M HCl solution?
.061
Sugar is easily soluble in water and has a molar mass of 342.30 g/mol. What is the molar concentration of a 249.8 mL aqueous solution prepared with 72.9 g of sugar?
.853
How many kilometers is 3038.6 cm?
0.030386
A block has a mass of 4.794 g and a volume of 132.3 cm3. Calculate the density in g/cm3.
0.03624
Determine whether or not each combination of substances can be used to create a buffer.
0.05 M HNO2, 0.05 M NaNO2:Buffer 1 M Na2HPO4, 1 M NaH2PO4:Buffer 0.1 M NH4Cl, 0.1 M HCl:Not a buffer 0.1 M HCl, 0.1 M KCl:Not a buffer 0.4 M KOH, 0.2 M NaOH:Not a buffer
Suppose you have 450.0 mL of a 0.250 M sodium hydroxide solution. How many moles of sodium hydroxide are in the solution?
0.113
Suppose you have 350.0 mL of a 0.450 M sodium hydroxide solution. How many moles of sodium hydroxide are in the solution?
0.158
Calculate the moles of ammonia present in a 5.366 g sample of ammonia, which has a molar mass of 17.030 g/mol.
0.3151
Suppose a student titrated vinegar, which is an acetic acid solution, of unknown strength with a sodium hydroxide solution according to the following equation. HC2H3O2+NaOH→H2O+NaC2H3O2 If 16.36 mL of 0.1506 M NaOH were required to titrate 5.00 mLof HC2H3O2. What is the percent (mass/volume) of the vinegar? The molar mass of acetic acid is 60.1 g/mol
2.96%
Based on the change in the nuclear symbol, determine what type of nuclear decay occurred.
23090Th⟶22688Ra:Alpha decay 15266Dy∗⟶15266Dy:Gamma decay 8737Rb⟶8738Sr:Beta decay
How many total valence electrons are present in a molecule of PCl3?
26
Carbon-11 is a radioisotope used in cancer imaging applications and has a half-life of 20.38 minutes. If 1.94 μg remain after 1.35 hours, how many micrograms were in the sample originally?
31.04
A 24.5 g sample of solution has a density of 0.768 g/mL. What is the sample volume (in mL)?
31.9mL
A series of measurements in the lab led to an experimental result of 32.9 mL, with a calcul
32.9 ± 0.3 mL
What is the correct reading of the volume in the pictured buret? Make sure to report your reading with the appropriate significant figures.
39.95 mL
Identify the value of each number presented in scientific notation.
4.65×10−^3=0.00465 4.65×10^3=4650 7.32×10^−4=0.000732 7.32×10^6=7320000
What is the correct reading for the graduated cylinder in the close-up? Make sure to report your reading with the appropriate significant figures.
40.5 mL
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.
Identify the safety equipment designed to deal with each emergency listed.
Chemicals on clothes : safety shower Cuts or minor burns: first aid kit Fire on a person: fire blanket Large fire on the bench top: fire extinguisher Chemical in eyes: Eyewash station Small benchtop fire: Overturned beaker
Determine whether each of the given characteristics refers to electrolytes or non-electrolytes.
Dissociate in solution:Electrolytes Do not dissociate in solution:Non-electrolytes Conduct electricity in solution:Electrolytes Do not conduct electricity in solution:Non-electrolytes Examples include C6H12O6and CCl4:Non-electrolytes Examples include NaOHand KBr:Electrolytes
Identify the factors that affect the intensity of radiation detected from a radioactive source.
Distance of the detector from the source Type of emission from the source Type of materials between the source and the detector
Identify the precautions to take with exits in the lab.
Do not block a door with an EXIT sign. Locate the exits prior to the start of lab
Mixtures are characterized by two fundamental properties:
Each of the substances in the mixture retains its chemical identity. Mixtures are separable into these components by physical means.
How can a solid dissolved in water be separated from the water?
Evaporation
Which process is used to separate soluble compounds from insoluble compounds?
Extraction
A crate of smoke detectors has a combined mass of 61.8 mg of americium-241, which has a half-life of 432.2 years. How many milligrams of americium-241 will remain after 1300 years?
7.73
How many total electron pairs are in the structure of CS2?
8
When drawing the Lewis structure of the HCCl3 molecule, the structure should represent a total of 26 valence electrons. What is the best description of the complete Lewis structure of the molecule?
A C atom should be in the center with single bonds to each Cl atom and a single bond to the H atom.
Identify the correct descriptions of beta particles.
A beta particle is a high-energy electron. A beta particle has a negative charge.
What information does not need to be included on a chemical waste label?
A description of the experiment the chemicals were used for
Which test is the confirmatory test for carbonate ion?
A drop of barium hydroxide
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.
Identify the correct descriptions of alpha particles.
An alpha particle is a helium nucleus. Alpha particles are more massive than beta particles.
Identify the types of information that are necessary to communicate with emergency responders.
Any other hazards present in the lab Any chemicals involved in an incident How the incident happened
When is the best time to clean glassware during the lab session?
As soon as practical after use
The equilibria studied in the lab procedure include which two reactants?
Fe3+ [CoCl4]2−
This is the process of separating a solid from a liquid by means of a porous material.
Filtration
Determine the relative order of the metric prefixes of kilo-, micro-, centi-, and milli-.
For the same base unit, micro- is less than milli-, which is less than centi-, which is less than kilo-.
In the reaction of magnesium metal with hydrochloric acid, how do you determine when the magnesium metal has reacted completely? Select all that apply. Mg(s)+2H+(aq) →Mg2+(aq)+H2(g)
Gas bubbles are no longer produced. The magnesium metal is gone.
Determine which items of personal protective equipment (PPE) you will likely use in a general chemistry lab.
Gloves, coat, googles
Which test is to be performed first on the unknown sample in the laboratory procedure Chemicals in Everyday Life?
H2SO4
Identify whether each substance is an acid or base.
HClO4:acid RbOH:base HNO2:acid Ba(OH)2:base KOH:base
Determine whether each statement describes a solution of a strong electrolyte, weak electrolyte, or non-electrolyte.
Has little or no conductivity: Nonelectrolyte solution Has the highest conductivity:Strong electrolyte solution Contains a completely dissociated solute:Strong electrolyte solution Has a medium level of conductivity:Weak electrolyte solution Contains a complete solute: Nonelectrolyte solution Contains a partially dissociated solute: Weak electrolyte solution
Identify the acid associated with each conjugate base.
I-:HI F-:HF NH3:Ammonium ion Cl-:HCl OH-:Water
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 recommendations Handling, storage, and reactivity information
Consider the two reactions of iron ions, one with thiocyanate ( SCN−SCN−) ions and one with chloride (Cl−Cl−) ions. Fe3++SCN−−⇀↽−FeSCN2 Fe3++4Cl−−⇀↽−FeCl4−
If you create an equilibrium mixture from Fe3+ and SCN−ions, adding Cl− ions will shift the iron-thiocyanate equilibrium to the reactant side because it removes iron from the iron-thiocyanate equilibrium mixture.
What are minor components in a mixture called?
Impurities
Where should glassware be stored after it is cleaned?
In a drying oven, or designated locations such as drawers or buret racks
Read the Safety Data Sheet (click SDS icon below) of hydrogen peroxide to identify the recommended way to store this substance.
In a tightly closed container in a dry and well-ventilated place
Identify the ions that will be tested in the Chemicals in Everyday Life procedure.
I− Cl− SO42− CO32− NH4+
Identify the correct equation for the equilibrium constant K for the reaction given. Cu(s)+2AgNO3(aq)−⇀↽−Cu(NO3)2(aq)+2Ag(s)
K=[Cu(NO3)2]/[AgNO3]2
When sodium chloride, NaClNaCl, dissolves in water, the solution contains sodium ions and chloride ionsin addition to the water solvent. The partial charges in water help dissolve the compound as the hydrogen end of water is attracted to the chloride ion and the oxygen end is attracted to the sodium ion.
sodium ions and chloride ions chloride ion sodium ion
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.
start by starting and stabilizing the stir function. a medium heat setting turn up the heat setting after
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.
thick gloves or dustpan . carefully collect all the broken glassware. broken glass container.
The stability of radioactive nuclei is often discussed with the kinetic term of half-life. A half-life is the amount of time required for 50% of the sample to decay. A more stable nucleus has a longer half-life.
time 50% longer
Determine where to dispose of each type of waste.
titrant solution-nalgene bottle with cap unused solid reagent=solid waste container broken flask-box lined with puncture resistant bag syringe tips- sharps container
Determine whether each of the molecules below is polar or nonpolar.
Linear CS2: Nonpolar Tetrahedral CCl4:Nonpolar Tetrahedral CH3OH:Polar Trigonal pyramidal NH3:Polar
Determine whether each of the molecules below is polar or nonpolar.
Linear N2:Nonpolar Tetrahedral CH4:Nonpolar Linear CO2:Nonpolar Bent H2O:Polar
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
Which of the following would not be helpful in separation a mixture of sand and salt?
Magnet
Which of the following properties is an extensive property?
Mass
Most of the matter people encounter in everyday life consists of mixtures of different substances.
Matter Mixtures
Most chemicals can be cleaned up with a general spill kit, but a few chemicals require specialized spill procedures. For each substance listed, determine whether a general spill kit is sufficient or if a specialized spill kit is needed.
Mercury: Special Phosphoric acid: General Methanol: general Hydrofluoric acid: special Acetone: general
Predict the products of hydrobromic acid, HBr, reacting with magnesium hydroxide, Mg(OH)2.
MgBr2 H2O
Mixtures are combinations of two or more substances.
Mixtures
While setting up a beaker to boil a solution on a hot plate, you notice that the stirring is erratic and unstable. What should you do to stabilize the stirring solution?
Move the beaker to the center of the hot plate. Turn down the stirring speed.
Identify the correct name of the given compounds.
NaHCO3:Sodium bicarbonate (NH4)2CO3:Ammonium carbonate NaCl:Sodium chloride NaI:Sodium iodide NH4Cl:Ammonium chloride
Determine whether or not each chemical formula is an empirical formula.
NaMnO4:Empirical formula CaCO3:Empirical formula Ba3(PO4)2:Empirical formula K2C2O4:Not an empirical formula C6H12O6:Not an empirical formula
To isolate a single variable when rearranging equations, move all other variables to the other side of the equation by using the opposite function on them and remembering to perform that operation on both sides of the equation. Make sure the rearrangement has the target variable in the numerator, not the denominator.
Other side The opposite function On both sides of the equation in the numerator, not the denominator
The separation of the components of a mixture is based upon the fact that each component has different physical properties. The components of a mixture are separated based on their physical properties.
Physical Physical
Whereas pure substances have fixed compositions, the composition of mixtures can vary.
Pure Fixed Mixtures
_______________________ is an area of chemistry concerned with the identification of substances.
Qualitative analysis
When any reversible reaction is at equilibrium, what conditions are necessarily true?
Reactants and products are both present in the reaction mixture. The rate of the forward reaction equals the rate of the reverse reaction. The amounts of reactants and products has stopped changing.
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.
How should spill cleaning materials be discarded?
Seal in a labeled plastic bag, then place in the solid waste container.
Sublimation is a phase change from solid to gas. The liquid phase is not present in this change.
Solid Gas Liquid
What is a confirmatory test?
The second test on a sample that is used to support the identity of a single ion or substance
At what times should a pH electrode be submerged in a solution?
When being stored in a storage cabinet When not being used between measurements When monitoring a reaction in a beaker
Determine when you should remove your goggles in the lab room.
When everyone in the room is done handling any chemicals or glassware
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
When using the Tare function on a balance, start by
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.
In order to use a pipet, place a bulb or pump at the top of the pipet. Use this object to fill the pipet such that the meniscus of the liquid is even with the volume line. Release the liquid, touching the tip of the pipet to the side of the container if necessary to release the last drop outside the pipet tip.
bulb or pump meniscus outside
In general, which characteristics are necessary for a location to be suitable for chemical storage?
cool dry dark
When using acids and bases, note that these substances are corrosive. Make every effort to avoid contact with the skin and lab surfaces. Be sure to wipe up any spills immediately.
corrosive the skin and lab surfaces immediately
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.
grasp the exterior of one glove with a gloved hand, peel off the first glove a bare finger
Magnesium reacts with oxygen in the air when lit with a Bunsen burner. Unlike other reactions, you should not look directly at this reaction.
lit with a Bunsen burner look directly at
Alph and beta particles originate from the nucleus. Protection from radiation is necessary because if radiation passes through the body it can damage cells. Exposure to radiation can be limited by increasing the distance from the radioactive source.
nucleus cells distance
In order to use a pipet, place a
In order to use a pipet, place a bulb or pump at the top of the pipet. Use this object to fill the pipet such that the meniscus of the liquid is even with the volume line. Release the liquid, touching the tip of the pipet to the side of the container if necessary to release the last drop outside the pipet tip.
Suppose you mix an unknown clear liquid with water and the added liquid mixes completely with the water so that no layers are visible. What is most likely true about the unknown liquid?
It is a polar liquid.
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.
1.3 (explanation down below) Start by converting the measured distances from yards to feet by remembering that 1 yard=3 feet. distance in feet=distance in yards×3 ft1 yddistance in feet=distance in yards×3 ft1 yd measured side in ft=120 yds×3 ft1 yd=360 ftmeasured side in ft=120 yds×3 ft1 yd=360 ft other measured side in ft=53.333 yds×3 ft1 yd=159.9999 ftother measured side in ft=53.333 yds×3 ft1 yd=159.9999 ft Then calculate the area of the field in square feet. area in ft2=measured side in ft×other measured side in ftarea in ft2=measured side in ft×other measured side in ft area in ft2=360 ft×159.9999 ft=57596.4 ft2area in ft2=360 ft×159.9999 ft=57596.4 ft2 Finally, convert area in square feet to acres. area in acres=area in ft2×1 acre43560 ft2area in acres=area in ft2×1 acre43560 ft2 area in acres=57596.4 ft2×1 acre43560 ft2=1.32223 acres=1.3 acresarea in acres=57596.4 ft2×1 acre43560 ft2=1.32223 acres= 1.3 acres There are only two significant figures in 120 yards so your answer should be reported with two significant figures.
A 2.81 g piece of zinc (density = 7.14 g/mL) is added to a graduated cylinder that contains 12.13 mL H2OH2O. What will be the final volume reading on the graduated cylinder, in mL?
12.52
Knowing that one day is 24 hours and one hour is 60 minutes, how many minutes are in 9.2 days?
13000
Calculate the volume of a box, in cubic centimeters, which is 423 cm long, 12 cm wide, and 25 cm high. Report your answer with correct significant figures in cubic centimeters.
130000
What is the correct way to report the length of the rectangle in centimeters?
15.60
Calculate the percent by mass of a solution made from 14 g NaCl (the solute) and 61 g water.
19
Suppose you need to prepare 136.2 mL of a 0.321 M aqueous solution of NaCl. What mass, in grams, of NaCl do you need to use to make the solution?
2.55
A graduated cylinder contains 10.00 mL water. A 14.74 g piece of aluminum is added to the water, and the volume rises to 15.46 mL. What is the density of the aluminum in g/mL?
2.7
Identify each described physical separation technique.
A solvent is added to dissolve only one mixture component and then the liquids are separated:Extraction A solid mixture is heated. One component transitions directly between solid and gas:Sublimation A solid is caught on paper or a membrane while the liquid passes through:FiltrationA liquid is carefully poured out, leaving the solid behind in the container:Decantation
Complete the equation for the alpha decay of an Ac nucleus by selecting the correct values in the nuclear symbol of the product. 22589Ac⟶42α+AZX
A: 221 Z: 87 X: Fr
Using the letters on the image, identify each component of the Bunsen burner.
A: Barrel B: Air Inlet C: Gas inlet D: Gas regulator
Using the letters on the image, identify each component of the liquid waste set-up.
A: Funnel B: Primary Container C: Waste Label D: Secondary container
Using the letters on the image, identify the significance of each section on the NFPA diamond.
A: Health B: Flammability C: Reactivity D: Special Hazards
Complete the equation for the beta decay of a carbon nucleus by selecting the correct values in the nuclear symbol of the product. 146C⟶0−1β+AZX
A:14 Z:7 X:N
Complete the nuclear symbol for an isotope of phosphorus with 18 neutrons. AZX
A:33 z:15 X:P
A neutralization reaction is a reaction between an acid and a base that results in the formation of water and a salt.
an acid and a bade water a salt
Determine when to put on disposable gloves for work in the lab.
Before handling any glassware or chemicals for the experiment
When should lab participants look at the Safety Data Sheet (SDS) of a substance?
Before using the substance
Why is it important that you not breathe on the baking soda test?
Breath contains CO2 which can cloud the test.
What are the best practices while sharing a lab balance with other students?
Brush off any chemical dust around the balance after each use. Alert your TA or instructor about any issues with the balance.
Fill in the expression for the equilibrium constant Kc for the reaction given. A+2B⟷2C+DA+2B⟷2C+D
C2D Kc=-------- AB2
Refer to the periodic table to find the correct molar mass for each given element or compound.
C2H6:30.067 g/mol Cl:35.446 g/mol O2:31.998 g/mol S:32.059 g/mol O:15.999 g/mol CH4:16.042 g/mol
Which compounds could be represented by the empirical formula CH2
C3H6 C2H4 C8H16
Identify the additional test to perform if each of the given ions is believed to be present.
CO32−:Barium hydroxide solution SO42−:Barium chloride solution I−:Silver nitrate solution Cl−:Silver nitrate solution
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
Identify the impact if you change the number of each subatomic particle for an atom.
Change number of neutrons:Different isotope Change number of electrons:Different ion Change number of protons:Different element
When using a properly stabilized balance, how should you ensure that you get the most accurate mass reading possible?
Close the side shields on the balance during reading. Measure the mass of the sample at room temperature.
Identify the expected result from the first test if each of the given ions is present in the unknown sample.
Cl−:Colorless, pungent gas SO42−:No reaction I−:Violet or red-brown vapors CO32−:Colorless, odorless gas
What are the substances making up a mixture called?
Components
How should you prepare a buret for titration before loading it with titrant?
Condition the buret with titrant solution.
Determine whether the stopcock should be completely open, partially open, or completely closed for each activity involved with titration.
Conditioning the buret with titrant:Completely closed Close to the calculated endpoint of a titration:Partially open Filling the buret with titrant:Completely closed At the beginning of a titration:Completely open
A 7.298 g sample of copper reacts completely with oxygen, forming a copper oxide. The final mass of the copper oxide is 8.217 g. What is the formula of the copper oxide?
Cu2O
This is the process of separating a liquid from a solid (sediment) by gently pouring the liquid from the solid so as not to disturb the solid.
Decantation
Match each titration term with its definition.
Solution of known concentration that is slowly added to a solution of unknown concentration:Titrant When the required amount of one solution has been added to the second solution to complete the reaction:Endpoint Process of slowly adding a solution to react with another solution and determine the concentration of one of the solutions based on the reaction between them:titration A reagent added to the analyte solution that changes color when the reaction is complete:Indicator Glassware that allows a solution to be precisely and slowly added to another solution:Buret Solution of an unknown concentration that has another solution slowly added to it:Analyte
Determine where each type of cleaning solution should be discarded after use.
Solvent used to rinse chemicals out of a beaker: waste container Water used to rinse detergent out of a flask:sink Acid solution used to clean a crucible:waste container
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.
Mass is conserved in a reaction if the sum of the initial reactant masses equals the sum of the masses of the products
Sum Sum the products
Identify each term as a description of an electron geometry or a molecular geometry.
Tetrahedral for NF3:Electron geometry Arrangement of bonding and non-bonding electron domains:Electron geometry Arrangement of only the atoms in a molecule:Molecular geometry Trigonal pyramidal for NF3:Molecular geometry
For each atom, determine how many dots should be drawn around the element symbol in the Lewis structure for a lone, neutral atom.
The Lewis structure of an oxygen atom should have 6 dots drawn around the symbol O. The Lewis structure of a calcium atom should have 2 dots drawn around the symbol Ca. The Lewis structure of a nitrogen atom should have 5 dots drawn around the symbol N. The Lewis structure of an aluminum atom should have 3 dots drawn around the symbol Al. The Lewis structure of a fluorine atom should have 7 dots drawn around the symbol F.
In the titration setup in lab, the buret will be filled with base. During the titration, a beaker placed underneath will contain acid and indicator.
base acid indicator
The equation to calculate density is
The equation to calculate density is D=m/V, where D is the density, m is the mass, and V is the volume.
Which statement is true about a chemical reaction at equilibrium?
The forward reaction rate is equal to the reverse reaction rate.
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 gas law experiment multiple times, resulting in the average PV products reported here. Student A 1.19 x 106 ± 350000 Pa-mLStudent B1.2 x 106 ± 22000 Pa-mL
The more precise work was done by Student B because that student's data has a smaller standard deviation.
According to Le Châtelier's Principle, heat applied to an exothermic reaction will shift the reaction towards the reactants. Heat applied to an endothermic reaction will shift the reaction towards the products.
The reactants the products
Determine whether each description corresponds to an endothermic reaction or an exothermic reaction.
The reaction mixture feels warm from the outside:Exothermic The reaction mixture feels cool from the outside:Endothermic Heat is a product in the reaction:ExothermicHeat is a reactant in the reaction: Endothermic
Before running a titration, you calculate the expected endpoint. However, when performing the experiment, you pass the expected endpoint with no visible color change. What is the most likely problem with the titration set-up?
There is not enough indicator in the analyte.
Consider the proposed structure of carbon dioxide. Determine whether the structure is correct and justify your decision.
This structure is incorrect due to the total number of electrons.
Suppose you are given the mass of each element in a compound sample.
To calculate the empirical formula, start by converting the mass of each element to moles using each element's molar mass. Then, calculate the ratio between the elements by dividing the moles of each element by the smallest number of moles present.
What is the purpose of stirring a solution while it is being heated?
To help evenly distribute heat throughout the solution
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:True Chewing gum is okay in the lab as long as you don't blow bubbles:False Food items should not be brought into the lab:True Beverages are allowed in lab as long as they are in containers with lids:False
Identify the molecular geometry around the nitrogen atom highlighted red in the given organic molecule.
Trigonal pyramidal
The composition of homogeneous mixtures is ______________.
Uniform
Determine whether each of the properties described applies to volumetric or graduated glassware.
Used for applications in which great accuracy is needed:volumetric Designed to measure one specific volume of liquid:volumetric Capable of measuring a range of volumes of liquid:graduated
The composition of heterogeneous mixtures is ______________.
Variable
What is the main precaution to take if a Gas Cylinder sign is present in the lab?
Visually check that the gas cylinder is restrained but keep a safe distance from it.
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
When a vinegar and oil salad dressing separates into two layers, the oil floats on top of the vinegar. The density of the oil
When a vinegar and oil salad dressing separates into two layers, the oil floats on top of the vinegar. The density of the oil
Match each lab incident to the item of PPE that will protect you from it. Each item of PPE will only be used once.
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 While transferring a solution from a flask to a beaker, the solution accidentally spills down the front of the lab bench: Lab coat While checking on a stirring solution, the solution splashes up towards your face.: Goggles While picking up a buret, an unknown solution left by a previous solution drips onto your hand: gloves
Which is NOT a good source of information about the hazards that affect waste disposal in a chemistry lab?
Your lab partner
Predict the products of hydrochloric acid reacting with zinc metal.
ZnCl2 H2
Which of the following represents an alpha particle? A: 42He B: −10e C: 00γ
a
The radiation given off by a radioactive source can be measured with a Geiger counter. The weak radiation should be recorded in units of counts per minute because the lab sources are extremely low on the Curie scale. Radiation is a random event so it is best to make each measurement multiple times.
a Geiger counter counts per minute multiple times
Match each description to the correct term.
a value used to describe the amount of one substance dissolved in another: concentration a chemical that is dissolved:solute a liquid that dissolves another substance:solvent a liquid consisting of one substance dissolved in another:solution