Category: Chemistry

Determine the experimental conditions (pH, temperature, sample pre-treatment) that provide the most efficient extraction of REEs from U.S. Appalachian Basin clay.

Roanoke ,virgina Stewartsville,clay ,speciation and the characterizing .

Employ established sequential leaching methods to speciate REEs present within U.S.

Determine the experimental conditions (pH, temperature, sample pre-treatment) that provide the most efficient extraction of REEs from U.S. Appalachian Basin clay.

Investigate the benefit of common chelating agents to increase the extraction efficiency of REEs from U.S. Appalachian Basin clay. Possible chelating agents are Ethylene diamine tetra acetic acid (EDTA), nitrilotriacetic acid (NTA), and ethylenediamine succinic acid (EDDS).

Study the inhibition of REE leaching by ever-present phosphate (PO43-) ions in samples of environmental importance.

Determine the molar mass of the solute (benzoic acid) we need to use the mass of the benzoic acid andcalculate the number of moles of benzoic acid in the mixture because

Freezing Point Depression

Determine the molar mass of the solute (benzoic acid) we need to use the mass of the benzoic acid andcalculate the number of moles of benzoic acid in the mixture because

How do controlled experiments produce accurate and reliable results?Why do you think 8 people in group B reported feeling better?What was the initial observation?

How do controlled experiments produce accurate and reliable results?

http://bit.ly/3b5UQ17

View the gif above using the link or the QR code. In the space provided, make a claim on what you think is occurring in this gif. What could you do to test your claim to see if you are correct?Which group represents the control group?

What is the independent variable?

What is the dependent variable?

What should Dr. Farquart’s conclusion be?

Why do you think 8 people in group B reported feeling better?What was the initial observation?

What is the independent variable?

What is the dependent variable?

What should Rafael’s conclusion be?Which person is in the control group?

What is the independent variable?

What is the dependent variable?

What should Leah’s conclusion be?What was Lee’s hypothesis?

Which fish are in the control group?

What is the independent variable?

What is the dependent variable?

Look at the results in the charts. What should Lee’s conclusion be?What is the difference between accidental discoveries and scientific investigations?

What is the difference between qualitative and quantitative data?

Why is a scientific experiment limited to a single system?

Explain the difference between an educated guess and a scientific hypothesis.

What are controls and variables in a scientific experiment?

In science, what does the term theory mean?

How are models related to theories and hypotheses?

Describe how to use the “difference method” when performing mass determinations. Why are masses in the chemistry laboratory usually determined by the difference method (using a beaker to contain the object to be weighted, rather than just placing the object directly on the pan of the balance)?

Pre-Laboratory Questions

Describe how to use the “difference method” when performing mass determinations. Why are masses in the chemistry laboratory usually determined by the difference method (using a beaker to contain the object to be weighted, rather than just placing the object directly on the pan of the balance)?

Why should the mass of an object never be determined while the object’s temperature is above room temperature?

If you weigh a hot object on the balance, the reading will be higher, the same, or lower than if it had been weighed after it cools to room temperature?

Why should liquids never be poured on or near the balance?

Why are masses in the chemistry laboratory usually determined by the difference method (using a beaker to contain the object to be weighted, rather than just placing the object directly on the pan of the balance)?

ACTIVITY OF WET LABS MEASURING THE MASS & VOLUME OF OBJECTS AND SUBSTANCES

Choose a Solid Object whose mass you will measure and describe the Solid Object in the appropriate location on the Data sheet.

Choose a container to use for determining the mass of the Solid Object; this will be Container A. Describe the type of container used in the appropriate location on the Data sheet.

Determine the Mass of the Solid Object by subtracting the Mass of Container A from the Mass of Container A and the Solid Object. Record the value on the Data sheet.

Describe how to use the “difference method” when performing mass determinations.

Why are masses in the chemistry laboratory usually determined by the difference method (using a beaker to contain the object to be weighted, rather than just placing the object directly on the pan of the balance)?

Why should the mass of an object never be determined while the object’s temperature is above room temperature?

If you weigh a hot object on the balance, the reading will be higher, the same, or lower than if it had been weighed after it cools to room temperature?

Why should liquids never be poured on or near the balance?

 Calculate the percentage error and absolute error in the mass of iron in your iron tablet. Compare your result to the true value. Does your measured value agree, within the calculated error limits, with the Sandoz value?

Titration
Analysis and discussion (600 words)

Give a brief overview of a redox titration. Be sure to include the relevant redox equations for the reaction used in your experiment.

Compare the procedure used in this experiment to a published source (or sources) and comment on any similarities or differences you have found. The published source should NOT be an online student lab report or blog – it must be a proper academic source.

Give a critique of the design of your experiment and identify the major sources of uncertainty. How could the accuracy of the experiment be improved?

Calculate the percentage error and absolute error in the mass of iron in your iron tablet. Compare your result to the true value. Does your measured value agree, within the calculated error limits, with the Sandoz value?

Write a balanced double replacement reaction for each of the following sets of aqueous reagents. Be sure to include the phase of each species. For any set that is predicted to give a reaction, using the table on page X, indicate the observation that would be expected.

Questions Answer the following questions on a separate sheet of paper 1.

The sulfite ion, S032-, reacts with acid analogous to the way carbonate, CO32-, reacts. Write a balanced chemical equation, including phases, for the reaction of potassium sulfite with hydrobromic acid.

K2 SO– (41-)
\t6y kft A4,- 5°3

Write a balanced double replacement reaction for each of the following sets of aqueous reagents. Be sure to include the phase of each species. For any set that is predicted to give a reaction, using the table on page X, indicate the observation that would be expected.

(a) zinc bromide and magnesium acetate

(b) nitric acid and ammonium hydroxide (c) sodium sulfite and potassium hydroxide (d) ammonium carbonate and hydrochloric acid (e) potassium phosphate and calcium iodide (0 lead(II)nitrate and sulfuric acid (h) silver nitrate and lithium chloride

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