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These items concern waste handling in the Determination of an Equilibrium Constant Experiment. (Select the proper response to complete the sentence.)

(a) The wastes in the Determination of an Equilibrium Constant Experiment should be disposed of in the labeled container. (b) While working on the experiment, wastes should be kept in a labeled beaker at the bench.

his question deals with the wastes generated in the calorimetry lab.

) The waste solutions should be flushed down the sink with water (b) The metal samples should be returned to the containers on the side shelf .

Burets, pipets, and small volumetric flasks are accurate to about

0.01 mL

How accurate are the volumes measured with a serological pipet? (Select all that apply.)

0.01 mL

When a student was weighing out a sample, the balance display read "0.500 g." Which of the following is the correct way to record this value into a lab notebook? (Select all that apply.)

0.500 g

This exercise deals with waste disposal in the Freezing Point Depression experiment. Choose the answer that best completes the following statement.

All wastes should be placed in the labeled waste container .

In the video entitled "Using an Analytical Balance", Lindsey demonstrates weighing a solid into what on an analytical balance? (Select all that apply.)

An empty, clean and dry beaker.

When reading the meniscus of a volumetric flask, which of the following are acceptable? (Select all that apply.)

Bend down to view the etched line on the volumetric flask at eye-level. View the etched line on the volumetric flask at eye-level.

(a) What are the standard ways to make a solution of known concentration? (Select all that apply.)

Dissolve a weighed amount (known mass) of solid into a known volume of liquid. Dilute a known volume of stock solution into a known volume of liquid.

Please view the video "Using a Volumetric Flask." After transferring all of the solid from a weighing beaker into a volumetric flask, which of the following describes the step or steps to finish making the solution? (Select all that apply.)

Fill the volumetric flask with a significant volume anywhere from about from half-way to where the neck narrows. Stopper the flask and invert a few times to ensure complete mixing and that the solid is completely dissolved. Once the solid is dissolved, fill the volumetric flask almost to the etched line and finish adding solvent dropwise until the bottom of the meniscus is touching the etched line.

What actions should you take if you spill copper(II) sulfate solution on yourself?

Flush the affected area with water.

If any of the solutions in this experiment are spilled on skin or clothing, what is the first thing to do?

Flush with water

When using a volumetric flask, which of the following are true? (Select all that apply.)

If any solute is lost in transfer, the concentration of the resulting solution will be lower than the calculated value. If a volumetric flask is over-filled so that the bottom of the meniscus is above the etched calibration mark, the concentration of the resulting solution will be lower than the calculated value. If the solid is added to a volumetric flask after filling it with solvent, the concentration of the resulting solution will be lower than the calculated value. If a volumetric flask is filled so that the top of the meniscus is level with the etched calibration mark, the concentration of the resulting solution will be higher than the calculated value.

What should be done to waste solutions containing copper ion? (Select all that apply.)

It should be dumped in a beaker labeled "waste copper" on one's bench during the experiment. It should be disposed of in the bottle for waste copper ion when work is completed.

Which of the following are hazardous properties of sodium thiocyanate?

It's an irritant. It's toxic.

Which of the following are hazardous properties of nitric acid?

It's corrosive. It's an oxidant.

When operating the centrifuge, students should do which of the following?

Make sure that the lid is completely shut and the safety knob is turned to engage the safety switch. Centrifuge for approximately 30 seconds.

Which of the following statements is NOT true?

Molality includes the moles of solute and the volume of solvent

When placing test tubes in the centrifuge, what are the best practices?

Never put stoppers or other items in the centrifuge with your tubes. Place test tubes containing approximately equal volumes in opposite positions on the rotor.

Before using a pipet, it should first be conditioned. Please select the step or steps that are involved in properly conditioning a pipet. (Select all that apply.)

Pour some reagent into a beaker for use with the pipet. Dispose of the reagent into a waste beaker since it is now contaminated with whatever may have been on the pipet. Draw a small volume of reagent into the pipet, turn it sideways and rotate so all the walls are coated with reagent.

In the video entitled "Using a Volumetric Flask", Lindsey demonstrates a quantitative transfer. Which of the following practices are important to achieve a quantitative transfer when adding a solid to a volumetric flask? (Select all that apply.)

Rinse the weighing beaker with deionized water or the solvent being used, and add it to the volumetric flask. Make sure that no solid is spilled when pouring it from the weighing beaker through the paper funnel. Gently tap on the paper funnel so that no solid is left clinging to it.

In the video entitled "Pipeting Techniques", Lindsey demonstrates the proper use of which of the following? (Select all that apply.)

Serological pipets Volumetric pipets

When using a bulb with a pipet, which of the following are true? (Select all that apply.)

Solution should be drawn up only slightly above the calibration mark. The bulb should be held just firmly enough to the end of the pipet to make a seal. Once there is solution in the pipet, the bulb should be replaced with a thumb or index finger so liquid can be slowly released to the desired level.

(a) What is assumption we are trying to validate in Part A of the calorimetry experiment?

Styrofoam cups isolate the system and surroundings from the rest of the universe.

In the video entitled "Using an Analytical Balance", what does Lindsey recommend you use to clean the weighing pan before and after use? (Select all that apply.)

The brush that is provided.

What actions should be taken if you spill a corrosive chemical on your skin? (Select all that apply.)

The first thing I should do is flush the area with water. I should have my lab partner report the incident to the instructor.

Select all that are true for a titration of 0.20 M KHP with 0.20 M HCl as the titrant as compared to your titration with 0.20 M NaOH as the titrant in the lab. (Select all that apply.)

The initial pH would be the same. The equivalence volume would be the same.

(b) When pouring two liquids together in the Styrofoam cup calorimeters, why should care be taken to avoid splashing or spilling the liquid?

The mass of the liquids are part of the calculations; loss of mass affects accuracy.

Regarding the solution that remains in a pipet after gravity has drained it, which of the following are true? (Select all that apply.)

The remaining solution in a serological pipet should be gently expelled with a pipet bulb to complete the transfer. The remaining solution in a volumetric pipet should NOT be gently expelled with a pipet bulb to complete the transfer.

Based on your result for the equilibrium constant of this reaction, which of the following are correct about the reaction? (Select all that apply.) K=410

The sign on ΔH° cannot be determined from K. ΔG° is less than zero. The reaction favors product.

Select all of the following that are benefits of a pH titration that is monitored using a pH electrode. (Select all that apply.)

The titration does not have to be stopped exactly at the equivalence point. The identity of the analyte can usually be determined from the pH at the midpoint. An accurate visual indicator is not necessary.

In this experiment, a calibration curve, often called a Beer's Law plot, will be made. A calibration curve should have which of the following attributes? (Select all that apply.)

The x- and y-axes should be labeled with units as well as quantities. The command for getting an equation is "Add Trendline" in Microsoft Excel .Concentration is plotted on the x-axis. Absorbance is plotted on the y-axis.

Which hazards are associated with copper(II) sulfate?

Toxic/Irritant

When the centrifuge process is complete, students should do which of the following?

Wait for the rotor to come to a complete stop before attempting to remove your test tubes. Using the eyehole on top, monitor the spinning rate and open the lid only after the rotor has slowed significantly.

Once the reading on the analytical balance stops fluctuating, which of the following are true? (Select all that apply.)

You should record the mass in your lab notebook with a pen.

If you significantly overshoot your target weight on an analytical balance, which of the following actions are correct? (Select all that apply.)

You should use the spatula provided to remove excess material. the excess material should be considered waste and disposed of properly.

What clothing is appropriate for the laboratory?

a shirt that covers the shoulders (has sleeves) pants that extend to the ankles shoes that cover heels and toes shirt and pants that overlap 6"

When working with a buret, one should take care that

all these cautions should be observed.

Which of the chemicals is a respiratory hazard with vapors that should not be inhaled? (Select all that apply.)

ammonia

(a) Which of the following is not a colligative property?

density enhancement

(c) Which terms below are also descriptive of the heat of neutralization to be measured in Part C of this experiment?

enthalpy of reaction

What common colligative property will you be exploring?

freezing point depression

The solute in Part B of the experiment is which of the following?

lauric acid

When draining the pipet,

one allows the liquid to flow out with gravity, then touches the pipet tip to receiving vessel to remove the last drop.

Which of the chemicals is corrosive? (Select all that apply.)

phosphoric acid

Which of the following chemicals are listed as hazardous? (Select all that apply.)

phosphoric acid ammonia

It is good practice to "condition" a pipet before using it by

rinsing it with a few milliliters of the solution that will be pipetted

When working with a volumetric pipet, one adjusts the liquid level

so the bottom of the meniscus is at the scribed line on the pipet.

What solvent is used for this experiment?

stearic acid

Calorimeter

surroundings

Cold water

surroundings

calorimeter

surroundings

water

surroundings

Hot metal:

system

Reaction of solid dissolving:

system

A buret should be conditioned, then filled

to slightly below the top scribe mark (0.00 mL).