Analytical Chemistry Summary part 1 PDF

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Summary

Prefixes for Units the science that deals with the identification and quantification of the components of material systems. Analysis - the process of determining the level of any or all components in a material system. A branch of chemistry that deals with the separation, identification and quantifi...

Description

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the science that deals with the identification and quantification of the components of material systems. Analysis - the process of determining the level of any or all components in a material system. A branch of chemistry that deals with the separation, identification and quantification of chemical compounds. Qualitative and Quantitative analysis

The process involving many individual steps by which an analyte’s identity or concentration in a sample is determined.

FUNDAMENTAL UNITS OF MEASUREMENT •

SI units o Standardized system of units adapted by scientists throughout the world

Physical Quantity

Name of Unit

Abbreviation

Mass

Kilogram

kg

Length

Meter

m

Time

Second

s

Temperature

Kelvin

K

Amount of Substance

Mole

mol

Electric current

Ampere

A

Luminous intensity

Candela

cd

QUalitative AnalYS iS - An analysis that establishes the chemical identity of the species.

QUantitative

AnalYS iS

- An analysis that determines the relative amounts of analytes in numerical terms.

Luminous intensity the quantity of visible light that is emitted in unit time per unit solid angle. • Prefixes for Units

Prefix

Abbreviation

Multiplier

giga-

G

109

mega-

M

106

kilo-

K

103

deci-

d

10-1

centi-

c

10-2

milli-

m

10-3

micro

µ

10-6

nano-

n

10-9

pico-

p

10-12

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A numerical system in which numbers are

The exponent for the exponential term is equal to the number of places the decimal point has been moved ➢ Positive (+) n means a large number so the decimal moves to the right by n places. ➢ Negative (-) n means a small number so the decimal moves to the left by n places. ▪ A – coefficient ▪ 10n – exponential term When converting from standard notation to scientific notation ➢ If the number is one or greater you will have a positive exponent and move the decimal to the left. 5

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Exponent = # of spaces to be moved by decimal

Convert the ff: 93,000,000 0.0000037 1.53x106 2.37x10-3 ANSWERS: • • • •

9.3x107 3.7x10-6 1,530,000 0.00237

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In measurements there is always some amount of uncertainty.

8.0123698 x 10

If the number is less than one you will have a negative exponent and move the decimal to the right.

0.0000508

5.08 x 10

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# of spaces moved by decimal = exponent

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When converting from scientific notation to standard notation o

0.0000508

5.08 x 10

expressed in the form A x 10n where A is a number with a single nonzero digit to the left of the decimal place and n is a whole number

801236.98 •

If the exponent is negative you will have a small number (1) and move the decimal to the right. 5

8.0123698 x 10 2

0.05050 has four significant figures •

Zeros at the end of a number are NOT SIGNIFICANT in the number LACKS an explicitly shown decimal point

Ex. 59,000,000 has two significant figures 6010 has three significant figures

• A substance that is dissolved in a liquid is called a solute. The liquid in which the solute is dissolved is the solvent. Together they represent a solution. ▪ ▪

In laboratory science, biologic solute are components in the blood known as analytes Solvent is a biologic fluid called plasma.

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GUIDELINES FOR DETERMINING SIGNIFICANT FIGURES 1. All nonzero digits are significant 2. Zeros may or may not be significant •

Zeros at the beginning of a number are never significant

Ex. 0.0141 has three significant figures •

Zeros between nonzero digits are always significant

Ex. 3.063 has four significant figures 0.001004 has four significant figures •

Zeros at the end of a number are SIGNIFICANT if a decimal point is PRESENT in the number

Ex. 56.00 has four significant figures

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Molarity (M) is expressed as the number of moles per 1 L of solution.

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A solution that is 1.0 M contains 1.0 mole of solute per liter of solution

𝑀𝑜𝑙𝑎𝑟𝑖𝑡𝑦 ሺ𝑀ሻ =

𝑔𝑟𝑎𝑚𝑠 𝑜𝑓 𝑠𝑜𝑙𝑢𝑡𝑒 𝑔𝑟𝑎𝑚 𝑚𝑜𝑙𝑒𝑐𝑢𝑙𝑎𝑟 𝑤𝑒𝑖𝑔ℎ𝑡 𝑥 𝑙𝑖𝑡𝑒𝑟 𝑜𝑓 𝑠𝑜𝑙𝑢𝑡𝑖𝑜𝑛

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The concentration of solution can be describe in many ways Concentration is expressed as Molarity, Normality or Percent solutions (included are those expression of concentration that is routinely used in the clinical lab) Gram molecular weight is obtained by adding the atomic weight of the component elements

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MOLALITY Molality (m) is expressed as the amount of solute per 1 kg of solvent.

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𝑀𝑜𝑙𝑎𝑙𝑖𝑡𝑦 ሺ𝑚 ሻ =

𝑔𝑟𝑎𝑚𝑠 𝑜𝑓 𝑠𝑜𝑙𝑢𝑡𝑒 𝑔𝑟𝑎𝑚 𝑚𝑜𝑙𝑒𝑐𝑢𝑙𝑎𝑟 𝑤𝑒𝑖𝑔ℎ𝑡 𝑥 𝑘𝑔 𝑜𝑓 𝑠𝑜𝑙𝑣𝑒𝑛𝑡

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