POC LAB - Qualitative Analysis of Elements in Organic Compounds

Carbon

Element with an atomic weight of 6

Hydrogen

Element with an atomic weight of 1

Oxygen

Element with an atomic weight of 8

Nitrogen

Element with an atomic weight of 7

Sulfur

Element with an atomic weight of 16

Phosphorus

Element with an atomic weight of 15

Silicon

Element with an atomic weight of 14

Flourine

Element with an atomic weight of 9

Chlorine

Element with an atomic weight of 17

Bromine

Element with an atomic weight of 35

Iodine

Element with an atomic weight of 53

Qualitative Analysis

Systematic approach in identifying elements in organic compounds using qualitative chemical reagents which heavily relies on organoleptic approach

Cupric Oxide

upon heating this substance, carbon and hydrogen oxidized to carbon dioxide and water

Lime water

used to detect presence of CO2 after heating Cupric Oxide

Anhydrous cupric sulfate

used to detect presence of water after heating Cupric Oxide

clear solution becomes turbid

Positive result of CO2 reacts with Ca(OH)2 forming CaCO3 and H2O

white powder turns to blue

Positive result of H2O reacts with anhydrous CuSO4 forming CuSO4 • 5 H2O

Nitrogen, Halogens, and Sulfur

Organic compounds that do not ionize and are covalent bonds

Sodium Metal

Compound fused in covalent organic compounds to convert into inorganic compounds

Lassaigne’s Extract

alkaline solution obtained by extracting the fused mass in water

Sodium Cyanide (NaCN)

This reaction creates what product?

Sodium Halide (NaX)

This reaction creates what product?

Sodium Sulfide (Na2S)

This reaction creates what product?

Blue

The litmus paper must turn this color after being moistened with ammonia gas from heating amino nitrogen

Pungent Odor

Positive result of Soda Lime Test

Beilstein Test

it is a flame test used to detect presence of halogens

Green Colored Flame

Positive result of Beilstein Test

Negative Result

result of fluorine under beilstein test

Positive Result

indicates presence of halogens/organic compounds based on the test

Silver Nitrate Test

the halogen reacts with silver nitrate in the presence of dilute nitric acid forming insoluble silver halide

White to light yellow precipitate

Positive result of presence of silver halide under silver nitrate test

Lead Acetate Test

test for identifying presence of sulfur

brownish-black precipitate

Positive result of sulfur upon reaction with lead acetate

Cysteine

amino acid found in Albumin

PbS

reacts with cysteine forming a black precipitate

Heating

causes the breaking of the polypeptide chain

Ferrox Test

Test that uses iron (III) hexathiocyanatoferrate or ——- paper to identify the presence of oxygen

red to reddish-purple color

Positive result of the ferrox test

ferrox paper

prepared by soaking a filter paper in methanol with equal parts of ferric chloride and ammonium thiocyanate

deep red colored solution

complex FeSCN2+ yields what color