FINAL

A calorimeter is used to measure the enthalpy of a reaction. Label the system and the surroundings.

"Calorimeter + air = surroundings; Contents = system"

Label the important components of a filtering flask set-up.

"[TOP→BOTTOM] = Buchner Funnel, Solids collect here, Vacuum tube hooks here, Liquid collect here"

Identify the key features of a buret by labeling the image below

"[TOP→BOTTOM] = barrel, stockcock, tip"

Which of the following images shows a filter flask? Select one:

"d - the one that looks like a funnel"

Which of the following hazards is not associated with the NaOH standardization experiment? Select one:

"flammable (GHS label)"

When you drop a block of metal into the water, you find that the metal sinks. What happens if you drop a smaller block of the same metal into water? Place the metal piece in the correct location and place blank boxes in unused locations.

"the same thing, the metal sinks to the bottom"

In the standardization of sodium hydroxide experiment, the following data were obtained: the mass of oxalic acid dihydrate used was 0.267 g; the volume of sodium hydroxide used was 21.49 mL. What is the molarity of the NaOH? (The molar mass of oxalic acid dihydrate is 126.07 g/mol) Helpful Equation: H2C2O4 (aq) + 2 NaOH (aq) → Na2C2O4 (aq) + 2 H2O (l) Do NOT include the units of M in your answer.

0.197

The following data were collected by a student performing the calorimetry experiment. From these data, determine the specific heat of the metal. Specific heat of water is 4.184 J/g·°C. mass of metal, mmet = 57.224 g mass of water in cup, mw = 72.125 g temp of boiling water, Tbw = 97.11°C initial temp of water in cup, Ti = 21.05 °C maximum temp after metal was added, Tmax = 29.89 °C qw = (specific heat of H2O)(mw)(ΔTw) qmet = (specific heat of metal)(mmet)(ΔTmet) Do NOT include units in answer.

0.694 "(0.6935)"

The volume reading of the buret in the following image is ______ mL. Only include numbers and decimals to the correct significant figures. Do NOT include units.

14.51 "(meniscus right below 14.5)"

A student is given a sample of copper(II) chloride hydrate. He places the sample in a dry evaporation dish and weighs it, recording the information in the lab notebook. The student then heats the dish to a red glow for 10 mins and after waiting until the dish is cooled back to room temperature, reweighs the dish and content. The data collected can be found in the Table below. Table 1. Mass of hydrate Mass of evaporating dish (empty) = 58.662 g Mass of evaporating dish +sample (before heating) = 65.216 g Mass of evaporating dish +sample (after heating) = 62.491 g What is the weight percent of water in the hydrated salt? Do NOT include the % sign in your answer. Report your answer to FOUR significant figures.

41.58

How many significant figures would you record for the value on the balance in your lab notebook? [100.000 g]

6

In the nickel synthesis and analysis lab, you synthesized a purple Ni-en complex with a mass of 0.992 g. After determining the empirical formula of your Ni-en complex, you calculated a theoretical yield of 1.276 g. What is your percent yield for the reaction?

77.7

Read the thermometer and report the temperature with the proper number of digits. Only submit numerical value, do not include units. Answer must be submitted with correct significant figures to receive credit.

82.9 "(temperature gauge right below 83°)"

What is the chemical formula for aluminum phosphide? For answers with subscripts, include number after the chemical symbol. DO NOT INCLUDE SPACES!

AlP

Which of the following about lab safety is TRUE? a). Chemicals and other equipment should not be removed from the laboratory. b). Chipped or cracked glassware is okay to use. c). It is safe to taste and smell chemicals in the lab. d). A Bunsen burner may be left unattended while lit.

Chemicals and other equipment should not be removed from the laboratory.

What type of calorimeter will be used in this experiment?

Coffee cup calorimeter

Any HCl that is leftover once the Ni-en complex has been titrated can go down the sink with running water.

False

When performing a titration, one should pull down on the stopcock.

False

In part C, when testing the known solution for Co2+, NaF is added to the test tube because ________ can interfere with the results.

Fe3+

What is the chemical formula for sulfurous acid? Include appropriate state of matter . For answers with subscripts, include number after the chemical symbol. DO NOT INCLUDE SPACES!

H2SO3(aq)

What is the chemical formula for sulfuric acid? Include appropriate state of matter . For answers with subscripts, include number after the chemical symbol. DO NOT INCLUDE SPACES!

H2SO4(aq)

What is the chemical formula for hydrofluoric acid? Include appropriate state of matter . For answers with subscripts, include number after the chemical symbol. DO NOT INCLUDE SPACES!

HF(aq)

Your lab manual clearly states for you to allow your evaporating dish to cool to room temperature prior to weighing it? Why should you not weigh hot, or even warm, objects?

Hot objects weigh less than room temperature objects

What is the chemical symbol for potassium?

K

Which of the following items are appropriate clothing that minimize chemical exposures and injuries while in lab? a). Long-sleeve shirts and jeans b). Exercise shorts c). Tank tops d). None of the above

Long-sleeve shirts and jeans

In order to safely run a sample in a centrifuge, it is important to Select all that apply. Select one or more: - Ensure that the sample fills the centrifuge tube completely. - Make sure the centrifuge is not near the edge of the lab bench. - Balance the sample with a counterweight of the same mass directly across from it. - Make sure the sample is free from impurities.

Make sure the centrifuge is not near the edge of the lab bench.; Balance the sample with a counterweight of the same mass directly across from it.

You will need to stop titrating at the earliest signs of a color change. What can be done to help detect a color change?

Place a white piece of paper under (or behind) the flask

What steps should be taken after a titration?

Rinse the buret with the DI water and let dry upside down before placing it back into the drawer.

The experimental errors below could occur when performing a hydrate analysis experiment. Indicate how the data values would be different from what they would be in an error free experiment. Error: The hydrate sample was not heated long enough and was still slightly damp when weighed Initial mass of the crucible and hydrate ______ Mass of water lost during heating ______ The sample mass after heating ______

This value would be the same This value would be less This value would be greater

After weighing out a chemical in the balance room, it is NOT okay to leave the container open for the next person.

True

It is not important that you get exactly half of the metal sample in each trial.

True

It is not okay if your Ni(DMG)2 precipitate is not entirely dry when you reweigh it after it was removed from the oven.

True

When holding the test tube for mixing it is best to hold the tube at the top.

True

You should have a striker at your work bench before turning on the gas.

True

You should use the same balance for all mass measurements in the hydrate experiment.

True

When electrons are excited from the ground state to excited state, requiring energy,this process is called ______

absorption

Before leaving lab, you should make sure a). your work area is clean b). all water, gas, and electrical equipment is turned off c). your lab equipment is placed in your assigned drawer d). all of the above

all of the above

Broken glassware in the lab is a hazard because: a). if left on the floor, someone might cut their foot after stepping on it b). if left on the lab bench, someone might cut their arm after leaning on the lab bench c). if in the sink, someone might cut themselves trying to dispose of it properly d). all of the above

all of the above

Common ways for chemicals to enter the body include a). absorption through the skin or eyes b). inhalation of vapors c). ingestion d). all of the above

all of the above

Which of the following should you do before working with a bunsen burner? a). tie back hair b). put on goggles c). check for cracks in tubing d). wear appropriate clothing e). all of the above f). none of the above

all of the above

Goggles must be worn on your eyes in the laboratory

at all times as a form of personal protective equipment

The existence of quantized energy levels in an atom can be inferred from

atomic spectral lines

When titrating the Ni-en complex with HCl acid the color of the solution goes from ______ to ______.

blue, yellow

Which of the following is a transition metal complex? a). pure cadmium b). cobalt in Vitamin B-12 c). sucrose, which contains C, H, and O d). pure silver

cobalt in Vitamin B-12

All reagents for the Qualitative Analysis experiment will be found on the side benches, with the exception of the following: Select all that apply. Select one or more: - 3% hydrogen peroxide - concentrated ammonium hydroxide - concentrated and dilute nitric acid - concentrated and dilute hydrochloric acid

concentrated ammonium hydroxide; concentrated and dilute nitric acid; concentrated and dilute hydrochloric acid

The unit for density in the experiment is ______

g/mL

When filtering both the Ni-en complex and the Ni(DMG)2 it is important to use the ___________ to direct the flow of the precipitate onto the filter paper.

glass stirring rod

Fill in the blank with the correct answer. The equipment used to measure volume is the ______ The equipment used to measure mass is the ______ The equipment used to measure density directly is the ______

graduated cylinder balance hydrometer

Calorimetry measures which quantity?

heat

Density is a(n) ______ property, meaning it is ______ on the amount of matter present.

intensive, independent

An element emits a spectrum that

is unique to that element

Which of the following lab equipment was used to conduct the calorimetry experiment. Check all the apply. Select one or more: - large test tube - large graduated cylinder - clamp - Vernier hand held unit - ring stand - 250 mL beaker - Erlenmeyer flask - evaporating dish - iron ring - hot plate - balance

large test tube; clamp; Vernier hand held unit; ring stand; iron ring; hot plate; balance

What is the chemical name for MgSO4•7H2O? Spelling and spacing matter, make sure to follow the spacing rules outlined in your textbook and only put 1 space between words.

magnesium sulfate heptahydrate

The unit for molarity is defined as

moles of solute/liter of solution

What is the chemical name for NO? Spelling and spacing matter, make sure to follow the spacing rules outlined in your textbook and only put 1 space between words.

nitrogen monoxide

Which of the following is not considered lab safety equipment? a). chemical spill kit b). fire blanket c). eye wash d). paper towels

paper towels

During the first filtration process it is important to gather as much of the synthesized Ni-en complex as possible or it will affect the _______ calculation.

percent yield

Determine the correct chemical name of H3PO4(aq)? Spelling and spacing matter, make sure to follow the spacing rules outlined in your textbook and only put 1 space between words.

phosphoric acid

A cloudy solution indicates that a ______ has formed and to confirm this one should centrifuge the test tube. Spelling matters.

precipitate

Litmus paper turns ______ in color the presence of an acidic solution.

red

What is the chemical name for Na3N? Spelling and spacing matter, make sure to follow the spacing rules outlined in your textbook and only put 1 space between words.

sodium nitride

The Vernier handheld unit has a variety of probes that can be used to take measurements. Which of the following probes are not used in general chemistry labs (1110/1120) at Appalachian State? Select one.

spectrophotometer

In the equation c = λν, c represents the ______ of light.

speed

Weigh paper is ______ and filter paper is ______.

square, circular

In Part A, what is the first thing you were instructed in the experiment video to do for the QA experiment?

start a hot water bath

If you spill a large amount of a chemical on your body, you should

take off all of your clothes and use the safety shower

Long hair in the laboratory must be:

tied back and away from flames

Burets are TD devices. TD means _________________.

to deliver

What setting on the vortex allows for the vortex to mix only when activated with pressure?

touch

Chemists often must identify unknowns through qualitative analysis, which is ______. In the qualitative analysis lab, you will be using ______ as the property to identify unknowns.

using tests to find the presence of properties, solubility

When you finish working with chemicals, equipment and other lab substances, always

wash your hands thoroughly with soap and water