PAPER 1 Flashcards
(27 cards)
Na+ and F- have the same electronic configuration. Why is Na+ smaller than F-?
Na+ and F- have the same number of electrons in their valence shell but Na+ has more protons in its outer shell. This means that there is a greater pull from the nucleus on the electrons as the nucleus has a greater charge and therefore, the atomic radius of Na+ is smaller.
What is the structure and bonding of NaF?
NaF is a giant ionic lattice. This means there are strong electrostatic forces of attraction between the positive Na+ ions and the negative F- ions.
A HF compound can bond to form H2F. Explain how.
Through dative covalent bonding. The F shares two of its electrons with the H+ ionic
Draw and name the shape of SF6
Octahedral
Draw and name the shape of H2F+
Bent
What is the bond energy of C-F
484kj/mol
Explain the process of electrospray ionisation
sample dissolved in volatile solvent
then injected through a fine hypodermic needle giving a fine mist / aerosol
the tip of needle has high voltage
so each gains a proton as it leaves the needle
Which ion reaches the detector first?
The first compound mentioned
What is the KE of the ion
?
Calculate the percentage mass of MgO in the mixture
70 something percent
What is the half equation for Iodine ions to form Iodide
2I- -> I2 +2e-
What is the half equation for Cr2O3- in acidic conditions?
6H+ + Cr2O3 + 6e- -> 2Cr3+ + 3H2O
Combine the two half equations
6I- + 6H+ +Cr2O3 ->3I2 + Cr3+ +3H2O
What is the electronic configuration of Cr
1s2 2s2 2p6 3s2 3p6 3d5 4s1
What is the oxidation state of Cr in Cr2O3
+3
What is the equation for the extraction of Mg?
TiCl4 + 2Mg -> 2MgCl2 + Ti
What is the tens in ionisation energies of Period 2?
The overall trend is that the ionisation energies increase. However there are 2 exceptions. Boron has a lower ionisation energy than Be because Boron is on a higher orbital (2p rather than 2s) which means it is more easily lost as it is further. Also Oxygen has a lower ionisation energy than Nitrogen. This is due to the electron pair repulsion in the outer shell electrons of oxygen which make a valence electron of Oxygen easier to lose.
Find the Mr of the acids in the titration.
98 or 99
KC expression
Learn KC retard
What was the percentage uncertainty for the pipette?
0.06/25 * 100 = 0.24%
How would air bubble being present in the burette affect the experiment?
The measured value would be greater than the true value.
Why would washing down the flask with distilled water have no effect on the titration
Because it would have no effect on the number of moles of the acid
Find the moles of NO2
0.073
Find the moles of the equilibrium mixture
NO2 = 1.125 Cl2= 0.825
