inorganic chemistry practice errors Flashcards
explain in terms of equilibrium, why acidic conditions should not be used with cells containing CN- ions
H+ reacts with CN- to form HCN
so equilibrium shifts right and CN- is removed
suggest three advantages of using ethanol rather than hydrogen in a fuel cell for vehicles
ethanol is less flammable than hydrogen
ethanol is less volatile than hydrogen
ethanol is easier to store
define the term standard electrode potential
the electrode potential of a half cell compared to the standard hydrogen hal cell under standard conditions, i.e, 298K, 100KPa, and 1 moldm^-3
state two ways that hydrogen can be stored as fuels for vehicles
it can be stored on a solid material
it can be stored within a solid material
it can be stored in liquid form AND under pressure
state and explain the trend in atomic radius from Li to F (Li and F are in the same period)
atomic radius decreases because charge increases, due to the number of protons in the nucleus increasing
shielding stays the same
so there is a greater nuclear attraction between the outer shell electrons and the nucleus
the equation between chlorine and sodium hydroxide to form bleach and the conditions required for this reaction to take place
2NaOH + Cl2 –> NaCl + NaClO +H2O
room temperature and dilute NaOH
predict the structure and bonding of Barium Nitride
Giant ionic lattice
describe the trend of first ionization energy across a period
across a period, the atomic radius decreases
inner shielding stays the same
so nuclear attraction increases, and more energy is required to remove an electron from the atoms in the period
induced dipole-dipole forces act between which particles
molecules
describe the general trend of atomic radius across period 3
atomic radius decreases across period 3
why does magnesium have greater SECOND ionisation energy than strontium
Mg+ has a smaller ionic radius than Sr+
Mg+ experiences less shielding
so there is a greater nuclear attraction between the nucleus and outer electrons of Mg+ than Sr+
why is the boiling point of PH3 lower than that of NH3 (both are in the same group)
NH3 has hydrogen bonding while PH3 does not
Hydrogen bond stronger than induced-dipole dipole forces in PH3, so more energy required to overcome the forces in NH3
why is the boiling point of PH3 lower than the boiling point of AsH3 (As and P are all in the same group)
more electrons in AsH3 than PH3
so stronger induced dipole-dipole forces. therefore more energy is required to overcome the induced dipole-dipole interactions in AsH3
entropy
a measure of the dispersal of energy and disorder within the chemicals making up a system
formula for entropy
entropy of products- entropy of reactants
transition metals with only one electron in their 4s subshell
copper and chromium
explain how ligand substitution allows hemoglobin to transport oxygen in the blood
oxygen binds to the iron ion in hemoglobin
when oxygen is required, the bond breaks to release it
formula for calculating bond enthalpies
The formula for calculating bond enthalpies is:
ΔH = Σ (bond enthalpies broken) - Σ (bond enthalpies formed)
where ΔH is the enthalpy change of the reaction, and Σ (bond enthalpies broken) and Σ (bond enthalpies formed) are the sums of the bond enthalpies of the bonds broken and formed, respectively.
the standard state of iodine
The standard state of iodine is a solid at 25°C and a pressure of 1 atm. The standard state of an element is the physical state of the element at 25°C and a pressure of 1 atm. For iodine, the solid form is the most stable at room temperature and atmospheric pressure, and is therefore considered to be the standard state.
what is the unit of k if ln2/ t1/2 is used to calculate the value of k
s^-1
why do industries try to avoid increasing temperature to very high levels, in order to increase the yield of their products?
why do industries try to avoid decreasing pressure to very low levels, in order to increase the yield of their products
because high temperatures use large amounts of energy
low pressure gives a low rate of reaction, so the yield will be higher, but it will take much longer to produce the products
why do industries avoid using high pressures to maximize the yield of their products
high-pressure systems can be expensive to build and maintain, so industries must balance the benefits of higher yield against the higher costs of production
standard conditions required to measure the standard cell potential
298 K temperature
100Kpa pressure
1 mol per dm cubed of solution
what colour is the [Cu(H2O)6]2+
pale blue solution
when [Cu(H2O)6]2+ reacts with HCl, what does it form
what colour is this new solution
[Cu(Cl)4]2-
yellow solution
[Cu(H2O)6]2+ reacts with KI to form
what are the colors of the individual products
CuI and I2
white solid for CuI
brown solution for I2
[Cu(H2O)6]2+ reacted with NH3 forms
[Cu(H2O)6]2+ reacted with excess NH3 forms
[Cu(NH3)6]2+
[Cu(NH3)4 (H2O)2]2+
an aqueous solution of ethanoic acid contains both hydrogen and hydroxide ions
how can an aqueous solution of acid contain hydroxide ions
water dissociates to form H+ and OH-
for a buffer solution to form, what needs to be present in the buffer
an acid and it’s conjugate base
bond enthalpy breaking of one mole of bonds in gaseous molecules
Enthalpy change of solution
Enthalpy change required for 1 mole of ionic compound to fully dissolve in water
Enthalpy change of solution
Enthalpy change required for 1 mole of ionic compound to fully dissolve in water
Formula for enthalpy change of solution
Sum of hydration enthalpies - lattice enthalpy
Average bond enthalpies
Average amount of energy required to break one mole of bonds in GASEOUS molecules
Is activation energy ever negative
No
Use of cis Platin In medicine
It is used in the treatment of cancer , although it has unpleasant side effects
colour of these transition metal ions
V3+
V2+
green
violet
