Predicting Chemical Reactions And Products Flashcards
What are alkali metals? How do properties change with the group?
Group 1 metals react with water to form alkaline solutions. Density increases and melting point decreases as you go down the group. Group 1 wants to lose an electron, atomic radius increases as you go down the group, attraction between electron and nuclei decreases, easier to lose shell, reactivity increases as you go down.
What are halogens? How does properties change down the group?
Elements found in group 7. As you go down the group, density, melting and boiling point increase. They need to gain electrons, atomic size increases as you go down, attraction decreases as you go down, harder to gain electrons and reactivity decreases as you go down.
What are displacement reactions?
A more reactive element displaces a less reactive ion from a compound or solution of its salts. A colour change is observed.
What are noble gases?
Noble gases are in group 8 and are monoatomic elements existing as single atoms because they have a full outer shell. They are all found in gaseous state, have weak intermolecular forces and are extremely unreactive.
What are transition metals? What are their uses?
They are metals found in between group 2 and 3. They are malleable, ductile, have varied ionic charges, varied electronic structure, high melting and boiling point, sonorous, lustrous, solid except Mercury, form coloured compounds and are good conductors.
They are used as catalysts, colour stained glass windows, colour paints and colour glazes on pottery.
What is the reactivity series?
Potassium, sodium, calcium, magnesium, aluminium, carbon, zinc, iron, tin, lead, hydrogen, copper, silver, gold, platinum
What are the gas tests?
Carbon dioxide is bubbled through limewater making it cloudy (white precipitate)
Hydrogen makes squeaky-pop sound around a lit splint
Oxygen relights a glowing splint
Chlorine bleaches damp blue litmus paper making it white
What is the flame test and its results?
Nichrome wire cleaned with dilute acid and heat. Wire dipped in solution put in a roaring flame.
Lithium = Red
Sodium = Yellow
Potassium = Lilac
Calcium = Orange-Red
Copper 2 = Green-Blue
RYLOG
What is the sodium hydroxide test and its results?
Metal hydroxides are soluble in water and different metals form different precipitates.
Iron 2 = Green
Iron 3 = Orange-Brown
Copper 2 = Blue
Calcium = White
Zinc = White
Aluminium and calcium dissolve in excess sodium hydroxide.
What are the instrumental methods of analysis?
Instrumental methods of analysis rely on machines to carry out analysis.
Highly precise, accurate, sensitive (small samples), no human intervention
Expensive, specialist knowledge
How do you test for anions in order?
Firstly test for carbonate by adding to a dilute acid and observing if bubbles are produced or use limewater (Calcium Hydroxide)
Next add hydrochloric acid to remove carbonate ions and add barium chloride to test for sulfate ions: white precipitate.
Lastly add nitric acid to remove carbonate ions then add silver nitrate where precipitate indicates ion. Chloride white, bromide cream, iodide yellow.
