OCR A-Level Chemistry A: Module 2 (Foundations in chemistry) overview quiz quiz

$1s^2 2s^2 2p^6 3s^2 3p^6 3d^9 4s^2$

$1s^2 2s^2 2p^6 3s^2 3p^6 3d^8 4s^2 4p^1$

$1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^1$

$1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^9$

$69.8$

$70.0$

$70.2$

$71.0$

$+3$

$+4$

$-3$

$+5$

A shared pair of electrons with one electron contributed by each of the two bonded atoms

A shared pair of electrons where both electrons come from one atom

The complete transfer of an electron from one atom to another, forming oppositely charged ions

An attraction between positive metal cations and a sea of delocalised outer-shell electrons

Trigonal planar, $120^\circ$

Tetrahedral, $109.5^\circ$

Pyramidal, $107^\circ$

Bent, $104.5^\circ$

The C=O bonds are not actually polar, because carbon and oxygen share the electrons equally

Carbon and oxygen have exactly equal electronegativity, so neither atom pulls the bond pair

It contains a dative covalent bond whose dipole opposes and cancels out the other bond dipole

It is a symmetrical linear molecule, so the bond dipoles cancel

$0.120\ mol\ dm^{-3}$

$0.0833\ mol\ dm^{-3}$

$0.150\ mol\ dm^{-3}$

$0.188\ mol\ dm^{-3}$

A strong acid is always more concentrated than a weak acid in any solution of the two

A strong acid fully dissociates, a weak acid only partially dissociates

A strong acid contains more hydrogen atoms per molecule than a weak acid does per molecule

A strong acid has a higher relative molecular mass than a weak acid for a given volume used

$Fe^{2+}$, the species that loses electrons in this reaction

$H^+$, which provides the acidic conditions for the reaction

$Cr_2O_7^{2-}$

$Fe^{3+}$, the iron product formed once the reaction is complete

Sodium chloride

Iodine

Magnesium

Silicon dioxide