chemical_anaysis Flashcards
(27 cards)
Pure substance
A pure substance is a single element or compound
Formulation
A formulation is a mixture of compounds in measured quantities that has been designed as a useful product.
Examples of formulations
Formulations include fuels
Alloys
Alloys are mixtures of metals; they are harder than pure metals
Paper chromatography
A start line is drawn near the bottom of the paper. The mixture is spotted on the line. A beaker is filled with small amount of solvent (it cannot touch or go above the start line when paper is placed in a beaker). Paper is hung on a rod and placed in a beaker. Solvent travels up the paper
Rf calculation
Distance moved by the spot / distance moved by solvent.
Rf value of 0.85
It has a higher affinity for the solvent than for the paper.
Hydrogen Test
Pop with burning splint over gas.
Oxygen Test
Glowing splint relights.
Carbon Dioxide Test
Turns limewater (Ca(OH)2) milky.
Chlorine Test
Bleaches damp litmus paper and makes it white.
Lithium Flame Test
Crimson red flame.
Sodium Flame Test
Yellow flame.
Potassium Flame Test
Lilac flame.
Calcium Flame Test
Orange red flame.
Copper Flame Test
Green flame.
Copper(II) Hydroxide Test
Forms a blue precipitate: Cu2+(aq) + 2OH−(aq) → Cu(OH)2(s).
Al3+
Ca2+
Iron(II) Hydroxide Test
Forms a dirty green precipitate: Fe2+(aq) + 2OH−(aq) → Fe(OH)2(s).
Calcium Hydroxide Test
Ca2+(aq) + 2OH−(aq) → Ca(OH)2(s).
Iron(III) Hydroxide Test
Forms a brown precipitate: Fe3+(aq) + 3OH−(aq) → Fe(OH)3(s).
Carbonate Anion Test
Add dilute acid
Sulfate Anion Test
Add a solution containing Ba2+ cations
Halide Anion Test
Add a solution of AgNO3 (acidified with HNO3); Chlorides - white precipitate
