Periodic table, balancing equations, and ionic bonding Flashcards
alkali metals reactions with water: lithium
fizzling/ bubbling
alkali metals reactions with water: sodium
fizzling/ bubbling, melts
alkali metals reactions with water: potasium
fizzing/ bubbling, melts, purple flame
alkali metals reactions with water: rubidium
sinks
alkali metals reactions with water: caesium
sinks, explodes
why does water have such strong reactions with alkali metals?
metal reacts with them to form a hydrogen gas and a (soluble) metal hydroxide (an alkali), highly exothermic reaction
word and symbol equation for alkali metals reactions with water
metal + water -> metal hydroxide + hydrogen
2M(s) + 2H₂O(l) -> 2MOH(aq) + H₂(g)
alkali metals reactions with oxygen
freshly cut metal is shiny but quickly tarnishes in air (the lower the elements are on the periodic table the quicker) if heated strongly, will burn in air
why does oxygen have such strong reactions with alkali metals?
metal reacts to oxygen to form a metal oxide
word and symbol equation for alkali metals reactions with oxygen
metal + oxygen -> metal oxide
4M(s) + O₂(g) -> 2M₂O(s)
group 1 alkali metals reactivity
gets more reactive the further down the group because the outer shell electron is further and more shielded from the nucleus, so it’s easier to be lost as there is a weaker electrostatic attraction
group 7 halogens reactivity
gets more reactive the further up the group because the outer shell electron is closer and less shielded from the nucleus, so it’s easier to gain an electron as there is a stronger electrostatic attraction
how to compare the reactivity of the halogens
see if they can displace each other from compounds (more reactive halogens displace less reactive halogens from the other compounds and can’t displace themselves)
what do we refers to the halogens when in compounds?
haides
fluorine state and room temperature, colour, solution colour
gas, colourless (pale yellow), colourless
chlorine state and room temperature, colour, solution colour
gas, green-yellow, pale green
bromine state and room temperature, colour, solution colour
liquid, red-brown, yellow-orange
iodine state and room temperature, colour, solution colour
solid, grey (purple vapour), brown
astatine state and room temperature, colour, solution colour (predicted)
solid, black/ dark grey, unknown
chlorine and potassium chloride reaction colour
no change/ stays colourless
chlorine and potassium bromide reaction colour
colourless to yellow (weak)
chlorine and potassium iodide reaction colour
colourless to brown (strong)
bromine and potassium chloride reaction colour
stayed yellow/ colourless
bromine and potassium bromide reaction colour
stayed yellow/ colourless
bromine and potassium iodide reaction colour
yellow turned brown (medium)
iodine and potassium chloride reaction colour
no reaction/ stayed brown
iodine and potassium bromide reaction colour
no reaction/ stayed brown
iodine and potassium iodide reaction colour
no reaction/ stayed brown
metals form __________ ions by __________ electrons
positive, losing
non-metals form __________ ions by __________ electrons
negative, gaining
ionic bonding
strong electrostatic forces of attraction between oppositely charged ions
how are ions arranged in an ionic compound
in a giant lattice (regular, repeated 3D arrangements of atoms/ ions)
why do ions with higher charges’ compounds have higher melting points?
because they have stronger electrostatic forces of attraction, taking more energy to overcome when melting
what do acids do in aqueous solutions?
dissociate or ionise to give H+ ions
why do ionic compounds only conduct electricity when molten or dissolved in water?
because their ions are free to move (conducting electricity is the flow of charged particles aka ions)
how much do strong acids dissociate, why and examples
fully dissociates because every molecule gives off H+ in solution, e.g. sulphuric acid, nitric acid, hydrochloric acid
how much do weak acids dissociate, why and examples
partially dissociate because only some molecules produce H+ in solution, e.g. ethanoic acid (vinegar)
bases
substances that will neutralise an acid to produce a salt and water
alkalis
bases that will also dissolve in water and produce hydroxide ions
example of bases
metal oxides and metal carbonates
examples of alkalis
group 1 hydroxides
salt
compound that could be formed when a metal or ammonium ion replaces the hydrogen in an acid
pH
measure of the hydrogen ion concentration of a solution, a result of both the concentration and degree of dissociation (strenth) of an acid
what does a lower pH mean?
a high H+ concentration
phenolphthalein indicator colour when pH=1/4/9/13
colourless, colourless, light pink, pink
methyl orange indicator colour when pH=1/4/9/13
red, orange, yellow, yellow
universal indicator indicator colour when pH=1/4/7/9/13
red, orange, green, blue, purple
equation for acids and metals
metal + acid -> salt + hydrogen
what happens in the reaction between acids and metals
bubbling/ fizzing -> metal dissolves
do all metals react with acids?
no, only metals that are more reactive than hydrogen
how to test for hydrogen gas?
hold a lit splint to it and it ignites with a squeaky pop
equation for metal carbonates with acid
carbonate + acid -> water + salt + carbon dioxide
what happens in the reaction between metal carbonates and acid
- metal carbonate dissolves
- bubbles of carbon dioxide gas gives off
symbol for carbonate
CO₃²-
how to test for carbon dioxide?
- bubble the gas through limewater
- if the limewater forms a white precipitate (turns cloudy) the gas is carbon dioxide
