CHEM 102L Lab Final Prep
16.1) Select all that apply: According to the background reading, our analysis will entail A) A titration curve B)A plot of temperature of solution over time C) A spectrum of the absorption of phenolphthalein D) A first derivative plot to confirm the point where moles of acid = moles of base
A titration curve, A first derivative plot to confirm the point where moles of acid = moles of base
16.2) If 0.119 g of an unknown diprotic acid is being titrated with 16.0 mL of a standardized concentration of the NaOH solution (0.107 M). What is the molar mass of the unknown acid? A) 139 g/mol B) 70 g/mol C) 25 g/mol D) other
A) 139 g/mol
11) The following items make up standard conditions for 1 mol of gas occupying 22.4 L volume: A) 273.15 K B) 298.15 K C) 0 atm D) 1 atm E) 760 atm
A) 273.15 K D) 1 atm
11) The independent variable for Parts D and E of this experiment is A) Amount of gas B) Volume C) Pressure D) Temperature E) Other
A) Amount of gas
11) What is the definition of an independent and a dependent variable? A) Independent variable is the variable in the experiment that changes; dependent variable is the variable that responds to the change of the independent variable. B) Independent variable is the variable in the experiment that remains the same; dependent variable is the variable that changes. C) Independent variable is the variable that when graphed is the y axis; dependent variable is the variable that when graphed is the x axis. D) Some other definition would be more correct.
A) Independent variable is the variable in the experiment that changes; dependent variable is the variable that responds to the change of the independent variable.
11) Hot glassware looks exactly like cold glassware. A) True B) False
A) True
11) R constants can be calculated because the pressure, volume, temperature, and amount of gas will be calculated or recorded in some capacity during this experiment. A) True B) False
A) True
13) True or False: A colligative property depends upon the number of solute molecules present and is not dependent upon the specific chemical identity. A) True B) False
A) True
15.1) Micropipettes will be used in this lab. This instrument allows for more accurate volume acquisition than a graduated cylinder. A) True B) False
A) True
15.1) Molar absorptivity coefficients are dependent upon every specific reaction. A) True B) False
A) True
16.1) Acids may have several equivalence points due to the presence of multiple protons. A) True B) False
A) True
16.1) We will be storing excess standardized solution for next week's lab: Experiment 16.2 Identification of an unknown acid. A) True B) False
A) True
15.1) Temperature is NOT a factor we will be considering this class period. However, the reaction in question is an exothermic reaction. Select all of the following conditions that will perturb the reaction to proceed in the forward direction. A) adding more reactant B) adding more product C) adding more heat D) removing heat E) adding an inert gas
A) adding more reactant D) removing heat
16.1) The inflection point is the greatest change in slope along the acid/base titration curve. The first derivative plot peak A) corresponds to the region of greatest slope, therefore an equivalence point in the titration curve. B) corresponds to the amount of titrant added to the titration. C) corresponds to the starting pH of the solution. D) corresponds to the volume needed to reach a pH of 7.
A) corresponds to the region of greatest slope, therefore an equivalence point in the titration curve.
15.1) The spectrophotometer requires what apparatus to collect data? (select all) A) cuvettes B) optical fiber cable C) Vernier Graphical Analysis software D) Vernier Spectral Analysis software E) syringes F) plastic transfer pipette
A) cuvettes D) Vernier Spectral Analysis Software
16.2) It is important to have proper technique in addition of the titrant to A) ensure all equivalence points can be observed. B) ensure only parts of the solution are being neutralized. C) ensure the reaction is making only products. D) proper technique is not necessary.
A) ensure all equivalence points can be observed.
12) Which of the following has a greater enthalpy of vaporization? A) greater surface area B) less surface area
A) greater surface area
11) If two variables are found to have an inverse relationship this means A) if one variable increases, the other decreases B) if one variable decreases, the other will stay constant C) if one variable decreases, the other decreases as well
A) if one variable increases, the other decreases
15.2) Last time, you determined two important quantities for [Fe(NCS)]2+, what were these two quantities? A) lambda max B) color of starting materials C) color of product D) molar extinction coefficient E) pH of nitric acid used to make the starting material F) pKa of the products
A) lambda max D) molar extinction coefficient
12) This liquid sample would experience the largest temperature change. A) less surface area B) more surface area
A) less surface area
12) In this lab, we will be measuring: A) temperature as a function of time B) temperature as a function of volume C) temperature as a function of viscosity D) temperature as a function of volts
A) temperature as a function of time
15.2) The ratio of reactants in each cuvette is smaller (iron nitrate and sodium thiocyanate) because this week: A) the reaction is being monitored at chemical equilibria B) there is less starting material available in Morehead labs C) the reaction is being shifted to completion D) the reaction is being monitored only with starting materials
A) the reaction is being monitored at chemical equilibria
15.2) The lamba max needed to solve for the equilibrium concentration of iron thiocyanate is: A) the same from 15.1 B) has to be calculated based on the spectrophotometer absorbance for 15.2 C) 350 nm
A) the same from 15.1
15.1) This reaction can be monitored informally by the color formation because: A) the starting materials are mostly colorless and the the product, iron thiocyanate, is colored B) the starting materials are colored and the product, iron thiocyanate, is colorless C) the starting materials and the product are colored
A) the starting materials are mostly colorless and the the product, iron thiocyanate, is colored
12) There should NOT be any liquid waste in this lab. A) true B) false
A) true
12) The following items are part of the experimental set-up when collecting data. Select all that apply. A) Vernier Temperature Probe B) solvent C) kim wipe D) stir bar E) vernier graphical analysis F) paper clip G) binder clip H) receiving beaker to catch excess solvent
A, B, C, E, G, H
15.1) You will be using all of the following equipment in some capacity in this lab. Select all that are applicable. A) 10 mL volumetric flask with a yellow plastic cap B) beaker C) Erlenmeyer flask D)Scintillation vials E) cuvettes F) glass pipettes G) plastic transfer pipettes H) micropipettes I) micropipette tips
A, B, D, E, G, H, I
11) The following items are part of the experimental set-up (any part) when collecting data. Select all that apply. a) Vernier Temperature Probe Choice 2 of 11:Alcohol Thermometer b) Syringe c) Stir bar d) Hot plate e) Vernier Pressure Sensor f) Vernier Graphical Analysis g) Vernier Spectral Analysis h) Erlenmeyer flask i) Beaker j) Plastic tubing
Alcohol Thermometer, Syringe, Hot plate, Vernier Pressure Sensor, Vernier Graphical Analysis, Erlenmeyer flask, Beaker, Plastic tubing
12) A temperature probe will be submerged in the solvent for: A) 10 seconds B) 30 seconds C) 45 seconds D) 60 seconds
B) 30 seconds
15.1) The Beer's Law relationship is how we will solve for the molar absorptivity coefficient. What is the equation that translates to the linear regression format? A) A = I/l0 B) A = m[analyte] + b C) C = Am D) C = Ae
B) A = m[analyte] + b
11) Does humidity impact data collection? A) Absolutely! There are more water molecules in the air. B) Absolutely not! We are assuming the moles of gas are constant because of the ideal gas (Avogradro's Law). C) Absolutely! The temperature and the pressure are different. D) Absolutely not! We will turn on the dehumidifiers at the student benches before starting any experiment.
B) Absolutely not! We are assuming the moles of gas are constant because of the ideal gas (Avogradro's Law).
15.1) The main purpose of experiment 15.1 is to: A) run a reaction B)Determine the relationship between the concentration of Fe(NCS)2+ and the absorbance to collect the value of molar absorption coefficient C) collect absorbances and discuss the chemical equilibrium D) solve the K value of the reaction E) to use Beer's Law to calculate the wavelength needed for spectrophotometry
B) Determine the relationship between the concentration of Fe(NCS)2+ and the absorbance to collect the value of molar absorption coefficient
11) This lab will have the most generated waste of all the labs so far. A) True B) False
B) False
16.2) A student weighed out KHP using the weigh-by-difference technique. They weighed the KHP vial, removed the cap, added a small amount of KHP to the Erlenmeyer flask, reweighed the vial, and recapped it. She performed the technique. A) True B) False
B) False
16.2) Ensuring the pH probe is immersed in the water solution and is charging is the appropriate way to store pH probes. A) True B) False
B) False
13) At different elevations, compounds can have different van't hoff factors. A) Pressure effects the ability for solute to dissolve in water. B) No, it depends on the identity of the solute. C) No, van't hoff factors are only dependent on the quantity of solute particles. D) Yes! The smaller the boiling point, the more likely ions will dissolve.
B) No, it depends on the identity of the solute.
16.2) What does having an unstandardized solution of sodium hydroxide (NaOH) mean? A) The temperature of the solution is too high to be used. B) The exact concentration has not been determined. C) The solution will likely react with moisture in the air. D) The base is not equally distributed in the solution so it needs to be stirred more.
B) The exact concentration has not been determined.
15.2) What do chemical equilibrium constants tell us about the reaction? A) The effect of temperature on the reaction B) The extent to which a reaction occurs C) The standardization of a desired solution D) The amount of moles needed to create a product
B) The extent to which a reaction occurs
13) True or False: The unknown was added to the same stearic acid sample used in Part C. A) False B) True
B) True
16.1) The proper method to load a burette with solution is A) on the bench top over the head B) at eye level (lowering the burette in the sink or acquiring a stool as necessary) C) without gloves so one can have a better grip
B) at eye level (lowering the burette in the sink or acquiring a stool as necessary)
15.2) The main purpose(s) for experiment 15.2 is to: A) determine the time it takes for all of the reactants to be consumed B) convert the absorption measurements to concentration of the product at equilibrium C) find the wavelength to collect absorbance values of iron thiocyanate D) determine the equilibrium constant for the reaction of NaSCN and Fe(NO3)3 to form [Fe(NCS)]2+ E) confirm the molar absorptivity coefficient from 15.1
B) convert the absorption measurements to concentration of the product at equilibrium D) determine the equilibrium constant for the reaction of NaSCN and Fe(NO3)3 to form [Fe(NCS)]2+
16.2) The main purpose for Experiment 16.2 is to A) determine the time it takes for the equivalence point to be reached B) determine the pka(s) of an unknown acid and thus identify the unknown titrated C) determine the equilibrium constant for the titration D) Confirm the concentration of sodium hydroxide from 16.1
B) determine the pka(s) of an unknown acid and thus identify the unknown titrated
11) The main purpose for Experiment 11: Gas Laws is to A) Learn about safety B) evaluate the mathematical relationships of pressure (P) with -volume (V), -amount of gas (n), and -temperature (T) of an ideal gas to calculate R C) Collect data and report the data D) Navigate through the procedure and connect the temperature probe, pressure sensors to the computer
B) evaluate the mathematical relationships of pressure (P) with -volume (V), -amount of gas (n), and -temperature (T) of an ideal gas to calculate R
12) When discussing intermolecular forces, electronegativities of atoms in molecules are not important. A) true B) false
B) false
12) This liquid sample would experience the fastest rate of temperature change. A) more surface area/linear B) less surface area/non linear
B) less surface area/non linear
12) Which of the following has a greater enthalpy of vaporization? A) less surface area B) more surface area
B) more surface area
12) Which of the following has the smaller enthalpy of vaporization? A) h bond B) no h bond
B) no h bond
16.1) In this lab, we will be measuring: A) pH as a function of time B) pH as a function of volume C) pH as a function of color D) pH as a function of volts
B) pH as a function of volume
15.1) What physical property of which compound are you monitoring? A) the pKa of reactant, Fe(NO3)3 B) the UV/visible absorption fo the product, [Fe(NCS)]2+ C) the UV/visible absorption of the reactant, Fe(NO3)3 D) the UV/visible absorption of the reactant, NaSCN
B) the UV/visible absorption of the product, [Fe(NCS)]2+
13) The main purpose for Experiment 13: Colligative Properties is to A) experimentally determine what the definition of molality is B) to identify an unknown acid dissolved in stearic acid through the colligative property of freezing point depression C) define what a colligative property is D) Navigate through the procedure and collect data
B) to identify an unknown acid dissolved in stearic acid through the colligative property of freezing point depression
15.1) A volumetric flask has the following characteristics: A) glassware that is designed to stand harsh condition like extreme heat and cold B) glassware that can give volumes 3 to 4 significant figures C) has a flat base D) can have a glass joint stopper E) can have a plastic joint stopper F) can have a metal joint stopper G) has a tare mark in the neck for the exact volume H) when swirling the flask to mix a solution, only the neck must be supported
B, C, D, E, G
16.2) Why are bubbles in the burette bad? A) The bubbles stem from using too strong of titrant so new solution must be prepared. B) It's a sign the titration is finished; they are not bad. C) It adds unnecessary error affecting the volume.
C) It adds unnecessary error affecting the volume.
11) The dependent variable for Parts B and C of this experiment is A) Amount of gas B) Volume C) Pressure D) Temperature E) Other
C) Pressure
11) The dependent variable for Parts F and G of this experiment is A) Amount of gas B) Volume C) Pressure D) Temperature E) Other
C) Pressure
11) If two variables are found to have a direct relationship this means A) if one variable increases, the other decreases B) if one variable decreases, the other increases C) if one variable decreases, the other decreases as well
C) if one variable decreases, the other decreases as well
12) The solvent soaked Kimwipes will be discarded A) in the trash B) in the glove recycling bins/boxes C) in the solid waste containers inside the chemical fume hood
C) in the solid waste containers inside the chemical fume hood
16.1) As part of conceptual understanding and the data, we will be using the dilution equation __ to make ___ M solution of NaOH. A) m1v1 = m2v2 : 1.0 B) pH = -log (H+); 1.0 C) m1v1 = m2v2; 0.1 D) pH = -log (H+); 0.1 E) other
C) m1v1 = m2v2; 0.1
16.1) In the titration experiment, we expect the indicator, ____ to change from ____ in acidic solutions to ____ in basic conditions. A) phenolphthalein; pink; colorless B) KHP; colorless; pink C) phenolphthalein; colorless; pink D) unknown acid; colorless; pink
C) phenolphthalein; colorless; pink
16.2) For Experiment 16, we are running a neutralization reaction. The titrant is ____ and it goes in the buret; the unknown acid goes in the ____ with a stir bar. A) water; beaker B) sodium hydroxide; vial C) sodium hydroxide; beaker D) sodium hydroxide; polyethylene bottle
C) sodium hydroxide; beaker
12) All of the following are the main types of intermolecular forces which pure solids can possess except: A) ion dipole interaction B) dipole dipole interactions C) van der wick forces
C) van der wick forces
13) A solution containing 20.0 g of an unknown non-electrolyte liquid and 110.0 g water has a freezing point of -1.32 °C. Given Kf = 1.86°C/m for water, the molar mass of the unknown liquid is ____g/mol. A) 28 B) 71 C) 128 D) 256
D) 256
15.2)What is the Equilibrium Concentration (M) of iron thiocyanate in this reaction given the values provided? A) 1.00 x 10^-3 M B) 2.00 x 10^-3 M C) 6.00 x 10^-3 D) 9.78 x 10^-5 E) other
D) 9.78 x 10^-5
15.1) The equilibrium below is the reaction of interest. In the preparation of the standard solutions, which reactant will be used in excess? Which reactant will essentially be converted entirely to product? Fe3+ + SCN- <--> [Fe(NCS)]2+ A) Fe(NO3)3 ; [Fe(NCS)]2+ B) NaSCN ; [Fe(NCS)]2+ C) NaSCN ; Fe(NO3)3 D) Fe(NO3)3 ; NaSCN
D) Fe(NO3)3 ; NaSCN
16.2) Why is it important to condition the burette? A) To determine the volume needed for the titration. B) To ensure that the solution will be stirring on a stir plate C) To minimize the amount of base that can be added to the buret. D) To ensure that all of the residual impurities are removed. E) Other
D) To ensure that all of the residual impurities are removed.
15.1) Le Chatelier's Principle states that: A) as temperature increase, the pH of a reaction also increases B) as a reaction reaches equilibrium, the K values increase C) a chemical reaction will spontaneously go to completion if enough energy is put into the system D) a chemical reaction will always restore equilibrium when perturbed
D) a chemical reaction will always restore equilibrium when perturbed
12) The main purpose for Experiment 12: Intermolecular Forces is to: A) learn about safety B) navigate through the procedure and connect the temperature probe to the computer C) collect data and report the minimum temperature D) determine how molecule structure and molecular weight of molecules influence the intermolecular forces between molecules and the enthalpies of vaporization
D) determine how molecule structure and molecular weight of molecules influence the intermolecular forces between molecules and the enthalpies of vaporization
12) As part of conceptual understanding and the data acquisition, we will be able to see the direct relationship of: A) total temperature change and solvent conductivity B) solvent conductivity and viscosity C) enthalpies of vaporization and names D) total temperature change and molecular properties
D) total temperature change and molecular properties
15.2) What is the Change in Concentration (M) of iron nitrate nonahydrate in this reaction? A) -2.00 x 10^-3 M B) +2.00 x 10^-3 M C) -6.00 x 10^-3 D) +6.00 x 10^-3 E) -9.78 x 10^-5 F) +9.78 x 10^-5 G) other
E) -9.78 x 10^-5
13) Describe the expected experimental apparatus you will use to determine the freezing point of the fatty acid samples. A) Large test tube and a small test tube were clamped over a beaker that have boiling water. The alcohol thermometer was placed in the water to monitor temperature. B) The smaller test tube was required to be wrapped around with a paper towel and fit into the larger test tube. The large test tube was secured on the ring stand using a clamp and it was positioned over the hot plate. A Vernier temperature probe will be placed inside the smaller test tube to record the temperature. C) The smaller test tube was required to be wrapped around with a paper towel and fit into the larger test tube. The large test tube was secured on the ring stand using a clamp and it was positioned over the hot plate that contained a water beaker. A Vernier temperature probe will be placed inside the beaker to record the temperature of the water. D) The larger test tube was required to be wrapped around with a paper towel and fit beside the smaller test tube. The large test tube was secured on the ring stand using a clamp and both tubes were positioned over the hot plate that contained a water beaker. An alcohol thermometer was placed inside the beaker to record the temperature. E) The smaller test tube was required to be wrapped around with a paper towel and fit into the larger test tube. The large test tube was secured on the ring stand using a clamp and it was positioned over the hot plate that contained a water beaker. An alcohol thermometer will be placed in the small test tube to monitor the temperature.
E) The smaller test tube was required to be wrapped around with a paper towel and fit into the larger test tube. The large test tube was secured on the ring stand using a clamp and it was positioned over the hot plate that contained a water beaker. An alcohol thermometer will be placed in the small test tube to monitor the temperature.
16.1) The main purpose for Experiment 16.1: Standardization of NaOH is to: A) Navigate through the procedure and make no mistakes B) Learn about safety C) Determine the necessary volume needed to make 0.1 M NaOH D) Determine the volume needed to titrate an unknown acid E) Titrate an unknown concentration of NaOH with KHP (potassium hydrogen phthalate) to determine the true concentration of the NaOH
E) Titrate an unknown concentration of NaOH with KHP (potassium hydrogen phthalate) to determine the true concentration of the NaOH
15.2) What is the Initial Concentration (M) of sodium thiocyanate in this reaction? A) 1.00 x 10^-3 M B) 2.00 x 10^-3 M C) 6.00 x 10^-3 D) 9.78 x 10^-5 E) other
E) other
16.1) How can a titration curve be defined? A)It is a plot that shows only the addition of titrant into a solution over time. B)It is a graphical description of the solution color change as the conjugate ion of the indicator is formed. C)It is used to calculate with more accuracy the equivalence point volume of the titration. D)It shows the starting pH of a solution and what happens over time upon heating. E)It is a graphical description of the solution pH as a function of the volume of added titrant.
E)It is a graphical description of the solution pH as a function of the volume of added titrant.
16.1) The following characteristics define what a primary standard is. Select all that apply. A) high in purity B) low in purity C) insoluble in water D) soluble in water E) unstable in air F) dries readily G) has a quantitative reactivity with the substance to be standardized H) reacts only partially to the substance being standardized I) has a detectable equivalence point with high accuracy J) doesn't have an equivalence point
High in purity, Soluble in water, Stable in air, Dries readily, Has quantitative reactivity with the substance to be standardized, Has a detectable equivalence point with high accuracy
13) The following freezing temperatures will be recorded in this lab. A) The pure solvent, water B) The pure solvent, stearic acid C) The solution of stearic acid with water D) The pure solvent, unknown acid E) The solution of stearic acid with an unknown fatty acid F) The solution of unknown fatty acid with water
The pure solvent, stearic acid, The solution of stearic acid with an unknown fatty acid
16.1) The following items are part of the experimental set-up when collecting data for any parts. Select all that apply. A) Vernier Temperature probe B) vernier conductivity probe C) vernier pH probe D) phenolphthalein E)kim wipe F) stir bar G) vernier graphical analysis H) hot plats I) stir plate J) beaker or flask containing dissolved KHP K) burette L) burette clamp
Vernier pH probe, Phenolphthalein, Kim wipe, Stir bar, Vernier Graphical Analysis, Stir plate, Beaker or flask containing dissolved KHP, Burette, Burette clamp
11) In this lab, what variables v pressure are being tested this week? Select all that apply. A) temperature B) voltage C) amount of gas D) volume E) weight
temperature, amount of gas, volume
