physical chemistry🧪 Flashcards
explain the trend in atomic radius from li to f
- atomic radius decreases
- increase in proton number
- electrons experience same shielding as same number of shells
- increase in nuclear attraction
state conditions and reagents for making bleach
- cold and dilute naoh
- chlorine
what is disproportionation
the simultaneous oxidation and reduction of the same element
equation for decomposition of calcium carbonate
caco3 (s) —> cao (s) + co2 (g)
which group 2 carbonate decomposes at highest temperature
BaCO3 or RaCO3
predict structure and bonding of Ba3N2
-giant ionic lattice
what second reagent is used to confirm halide test and results
- nh3
- agcl dissolves in dilute nh3
- agbr dissolves in concentrated nh3
- agi does not dissolve
when talking about ionisation energy of carbon why is it important to distinguish between diamond and graphite
diamond and graphite form gaseous atoms of carbon when ionised
force overcome when melting fluorine
induced dipole
in lithium, between which particles are metallic bonds acting
li+ ions and delocalised electrons
Al MP= 660
Si MP=1410
P MP= 44
explain trend in terms of bonding and structure
- silicon has giant covalent structure
- aluminium has giant structure and metallic bonds
- phosphorus has simple covalent molecules with induced dipole forces between molecules
- metallic and covalent bonds are stronger than induced dipole forces
-strontium sulfate (iv) why is roman numeral used
-sulfur has many oxidation states
what acid does sr(oh)2 react with to form srso3
h2so3
effect of increasing pressure on reaction rate
- increases rate of reaction
- more molecules per unit volume
- more frequent collisions
what is le chateliers principle
position of equilibrium will shift to minimise the effect of any change in conditions
why do catalysts reduce energy demand
-allows reactions to take place at lower temperatures
fermentation equation and conditions
C6H12O6–> 2C2H5OH + 2CO2
anaerobic
37 degrees
yeast
how do NO and CO react in catalytic converter
2NO+2CO—>2CO2+N2
how does position of equilibrium counteract higher temperature
as temperature increases position of equilibrium changes to minimise effect of temperature by absorbing energy
how is margarine made out of hydrogen
unsaturated vegetable oils and nickel catalyst
advantage disadvantage of biodiesel
biodiesel renewable
decrease need for fossil fuels
biodiesel more carbon neutral
but forests need to be cut down for land
does BaO or MgO have higher pH when added to water
BaO
ionic compound conductivity solid
does not conduct because ions are fixed in lattice and cannot move
solid is heated and the gas produced is collected in a gas syringe, how to get accurate result
- heat until syringe stops moving
- wait until gas has cooled before measuring volume
apparatus to separate two liquids eg hexane and sodium chlorate
separating funnel
why does free radical substitution produce many products
- substitution at different positions along chain
- more than one termination step
how does catalyst increase rate of reaction
- lower activation energy
- greater proportion of molecules exceed activation energy
strontium reaction with water
Sr + 2H2O —> Sr(OH)2 + H2
how is strontium carbonate converted to strontium oxide
heat
what colour does cyclohexane change in chlorine
orange
chlorine reaction with hot concentrated naoh
3Cl2 + 6NaOH —> NaClO3 + 5NaCl + 3H2O
sodium chlorate vii formula
NaClO4
why does magnesium have greater bp than sodium
- mg ions have greater charge
- mg has more outer electrons
- mg has greater attraction between ions and electrons
what is periodicity
repeating trend of properties across periods
why is experimental enthalpy change different to data book
- non standard conditions
- heat loss to surroundings
- incomplete combustion
what is average bond enthalpy
-average enthalpy change when 1 mol of gaseous covalent bonds is broken
