Homework Assignment 01 ...is from Chapter 1. Problems assigned are:

4,5,9,10,12,15,22,29,31 (pages 29 ff)

This assignment is due at class time Friday, Sept 10

Prepare on regularly sized paper, one side only with multiple pages stapled.

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Homework Assignment 01

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Chapter 2 – Tools of the Trade Analytical Balances

The actual mass of an object as measured in a vacuum is usually greater than the apparent mass measured in air due to the buoyancy effect. We will not apply buoyancy corrections to the masses measured in this course.

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Chapter 2 – Tools of the Trade Volumetric Glassware

Volumetric glass-ware a) a 50-mL glass buret and b) a digital titrator

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Chapter 2 – Tools of the Trade Volumetric Glassware

The glass buret is directly readable to 0.1 mL. You will subdivide the finest graduate marks by 10 to read the buret to 0.01 mL. The meniscus is read at the bottom of the curve, except for dark colored solutions such as iodine or permanganate.

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Chapter 2 – Tools of the Trade Volumetric Glassware

Be sure to work the air bubble out of the area between the stopcock and the tip before proceeding to titrate.

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Chapter 2 – Tools of the Trade Volumetric Glassware

Various forms of volumetric flasks. They also come in sizes from 2-L down to 1-mL

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Chapter 2 – Tools of the Trade Volumetric Glassware

The meniscus of the neck of the volumetric flask needs to be adjusted very carefully. I suggest using a dropper. The area above must be clean so that drops of solvent will not add to the total volume.

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Chapter 2 – Tools of the Trade Volumetric Glassware

Pipets come a variety of forms.a) 10-mL transfer pipet (TD) drain b) graduated pipet transfer pipet (TD) drainc) Ostwald-Folin 5-mL pipet (TC) blow out d) Serological graduated pipet (TC) blow out

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Chapter 2 – Tools of the Trade Volumetric Glassware

Microliter pipets

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Chapter 2 – Tools of the Trade Volumetric Glassware

a) Glass -liter syringe and b) digital dispenser for microsyringes

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Chapter 2 – Tools of the Trade Filtering Techniques

Filtration with a Gooch crucible. You will use a plastic check valve in place of the trap (right-most flask).

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Chapter 2 – Tools of the Trade Filtering Techniques

Folding filter paper to use with conical glass funnels

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Chapter 2 – Tools of the Trade Filtering Techniques

Quantitatively transferring the precipitate and solution onto the filter. The procedure is the similar anytime you are doing a quantitative transfer of a solution.

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Chapter 2 – Tools of the Trade Miscellaneous Lab Techniques

Protecting drying samples or standards in the oven

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Chapter 2 – Tools of the Trade Miscellaneous Lab Techniques

The desiccator provides for protection of materials that have been dried from the absorption of water vapor. b) is a vacuum desiccator

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Chapter 2 – Tools of the Trade Miscellaneous Lab Techniques

Glassware may be calibrated by measuring the mass of

water contained in or delivered by the glassware.

Since density = mass/volume, the volume is calculated.

For exact work the temperature is also measured and

the density at a given temperature used. The density as

a function of temperature may be obtained from the

CRC Handbook.

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Chapter 2 – Tools of the Trade Miscellaneous Lab Techniques

The microwave digestion bomb lined with Telfon used to decompose organic samples