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OFFICIAL UAT-UK SPEC: C17MODULE: CHEMISTRY1 Tested Topic

C17: Environmental Chemistry and Instrumental Analysis

Official Cambridge & Imperial ESAT specification requirements for Environmental Chemistry and Instrumental Analysis on the Chemistry paper. Understand the syllabus boundaries, spot distractor traps engineered by examiners, and master the 2-step Sub-90 shortcuts that compress solve time well below the 88.8-second cutoff.

Start 40-Min Timed Mock Explore 1 Tested Topics

Official Syllabus Subtopics

Requirements specified in the UAT-UK framework

  • 1Composition of dry unpolluted air: 78% N₂, 21% O₂, 0.9% Ar, 0.04% CO₂
  • 2Atmospheric pollutants: carbon monoxide, sulfur dioxide, nitrogen oxides (NOₓ), and particulates
  • 3Greenhouse gases and global warming mechanisms
  • 4Potable water purification: sedimentation, filtration, and chlorination
  • 5Diatomic mass spectrometry: molecular ion peak patterns from isotopes
  • 6Chlorine Cl₂ peak ratios (9 : 6 : 1 at m/z 70, 72, 74 from 3:1 ³⁵Cl/³⁷Cl)
  • 7Bromine Br₂ peak ratios (1 : 2 : 1 at m/z 158, 160, 162 from 1:1 ⁷⁹Br/⁸¹Br)

Sub-90 Exam Speed Tips

How top candidates solve this spec under the 88.8s clock

Speed Invariant #1

For diatomic molecules with two isotopes in ratio p : q, molecular ion peak intensities follow (p + q)² = p² : 2pq : q².

Speed Invariant #2

Chlorine-35 and Chlorine-37 in 3:1 ratio produce m/z peaks in 9:6:1 intensity.

Examiner Trap Alert

Examiners engineer distractor options using common algebraic expansions and sign slips. Always test structural ratios or invariants before calculating arithmetic values.

Tested Topics in Specification C17

Master the individual question patterns and Sub-90 shortcuts for this specification.

1 Topic Catalogued
ARCH-C-025 Past Qs (2.22%)

Diatomic Mass Spectrometry (m/z Peak Ratios 9:6:1 & 1:2:1) & Molecular Ion Combinations

Diatomic mass spectra follow (p + q)² = p² : 2pq : q². Memorise the two canonical ESAT ratios: Br2+ (1:1 isotopes at 79,81) -> 1 : 2 : 1 at m/z 158, 160, 162; Cl2+ (3:1 isotopes at 35,37) -> 9 : 6 : 1 at m/z 70, 72, 74.

Classroom: 140s→Sub-90: 35s
+105s Saved per Question
Topic Shortcut Guide →Shortcut Lesson →Practice Free Questions →
UAT-UK ESAT SPEED REVOLUTION

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