New syllabus: II
Old syllabus: +2
See 9.1 "Oxidation number and oxidation state are often used interchangeably, though IUPAC does formally distinguish between the two terms. Oxidation numbers are represented by Roman numerals according to IUPAC. • Oxidation states should be represented with the sign given before the number, e.g. +2 not 2+.

New syllabus: (E)-2-chlorobut-2-ene (or cis-2-chlorobut-2-ene)
Old syllabus: The geometric isomer cis-2-chlorobut-2-ene

See 20.3 "The term geometric isomers as recommended by IUPAC is now obsolete and cis-trans isomers and E/Z isomers should be encouraged in the teaching programme. In the E/Z system, the group of highest Cahn–Ingold–Prelog priority attached to one of the terminal doubly bonded atoms of the alkene (i.e. R1 or R2) is compared with the group of highest precedence attached to the other (i.e. R3 or R4). The stereoisomer is Z if the groups lie on the same side of a reference plane passing through the double bond and perpendicular to the plane containing the bonds linking the groups to the double-bonded atoms; the other stereoisomer is designated as E."

New syllabus: 15
Old syllabus: 5

See 3.1 "The group numbering scheme from group 1 to group 18, as recommended by IUPAC, should be used."

New syllabus: Measured at SATP (Standard Ambient Temperature and Pressure) 298 K and 100 kPa.
Old syllabus: Measured at STP (Standard Temperature and Pressure) 298 K and 1.01 x 10⁵ Pa.

See 2014 data booklet Section 2. "STP conditions = 273 K and 100 kPa SATP conditions = 298 K and 100 kPa" Note that both SATP and STP are at 1.00 x 10⁵ Pa. In the old programme it was 1.01 x 10⁵ Pa (or 1 atm). In the past there was confusion also about the temperature. For the gas laws the temperature of 273 K was taken but 298 K was taken when referring to thermodynamic quantities such as ΔH^⦵_f even though ⦵ was usually referred to as 'standard conditions'.

New syllabus: London (dispersion) forces
Old syllabus: van der Waals' forces

See 4.4 "The term “London (dispersion) forces” refers to instantaneous induced dipole-induced dipole forces that exist between any atoms or groups of atoms and should be used for non-polar entities. The term “van der Waals” is an inclusive term, which includes dipole–dipole, dipole-induced dipole and London (dispersion) forces."

New syllabus: 2.27 × 10⁻² m³ mol⁻¹ (= 22.7 dm³ mol⁻¹) measured at 273 K and 100 kPa
Old syllabus: 2.24 × 10^–2 m³ mol^–1 (= 22.4 dm³ mol^–1) measured at 273 K and 1.01 × 10⁵ Pa

See new data booklet.

New syllabus: Aspirin - phenyl, ester and carboxyl; Propan-2-ol - hydroxyl
Old syllabus: Aspirin - benzene ring, ester and carboxylic acid; Propan-2-ol - alcohol

See 10.1 "The distinction between class names and functional group names needs to be made. E.g. for OH, hydroxyl is the functional group whereas alcohol is the class name."

New syllabus: Yes
Old syllabus: No

See 13.1 and Section 14 of the new data booklet. The old syllabus specifically stated under assessment statement 13.2.2."Explain why Sc and Zn are not considered to be transition elements." The new syllabus just states that zinc is not considered a transition element.

New syllabus: 1s²2s²2p⁶3s²3p⁶4s¹ or [Ar]4s¹
Old syllabus: 2.8.8.1

This is a slightly trick question as the old syllabus actually called it electron arrangement not electron configuration. See 2.2 "Full electron configurations (eg 1s²2s²2p⁶3s²3p⁴) and condensed electron configurations (e.g. [Ne] 3s²3p⁴) should be covered."

New syllabus: Electron domain

See 4.3 "The term “electron domain” should be used in place of 'negative charge centre'."