CHEMISTRY EXAM PRACTICE - MARK SCHEME - Unit AS 1 Basic Concepts in Physical and Inorganic Chemistry

Sep 30, 2026

Mark scheme for “Chemistry Exam Practice” for CCEA AS, providing worked model answers and mark allocations for Unit AS 1: Basic Concepts in Physical and Inorganic Chemistry. Covers formulae, equations and amounts of substance, including acceptable alternative stoichiometry for enthalpy work in AS2. Includes ionic and molecular equation examples, Avogadro’s constant and mole calculations, relative molecular mass conversion to moles and particles, and mass-to-mole computations. Includes specimen answers with selected multiple-choice selections and supporting atom/molecule counts.

LanguageEnglish

CategoryExam

FormatPDF

Pages87

Reading Time3 h 39 min

AccessFree to download

Formulae, Equations and Amounts of Substance

Equations

Ionic and particulate equations

Avogadro’s constant, the mole and molar mass

Mole-to-particle calculations

Relative molecular mass to moles and particles

Alyn G McFarland Nora Henry CCEA AS CHEMISTRY EXAM PRACTICE MARK SCHEME This mark scheme is for use in conjunction with the book Chemistry Exam Practice for CCEA AS, ISBN: 978 1 78073 034 9 Colourpoint Educational An imprint of Colourpoint Creative Ltd Colourpoint House Jubilee Business Park 21 Jubilee Road Newtownards County Down Northern Ireland BT23 4YH Tel: 028 9182 0505 E-mail: [sales@colourpoint.co.uk](sales@colourpoint.co.uk) [Web site: www.colourpoint.co.uk](Web site: www.colourpoint.co.uk) ©2019 Alyn G McFarland, Nora Henry and Colourpoint Creative Ltd. All rights reserved. Updated with a minor corrections 2024. This material is provided solely for use with the accompanying textbook. Unauthorised reproduction, in whole or part, without prior written permission from the publisher is prohibited. Publisher’s Note: These answers have been written to help students preparing for the AS Chemistry specification from CCEA. While Colourpoint Educational and the author have taken every care in its production, we are not able to guarantee that it is completely error-free. Additionally, while the mark scheme has been written to closely match the CCEA specification, it is the responsibility of each candidate to satisfy themselves that they have fully met the requirements of the CCEA specification prior to sitting an exam set by that body. For this reason, and because specifications change with time, we strongly advise every candidate to avail of a qualified teacher and to check the contents of the most recent specification for themselves prior to the exam. Colourpoint Creative Ltd therefore cannot be held responsible for any errors or omissions in this mark scheme or any consequences thereof. v7 Unit AS 1: Basic Concepts in Physical and Inorganic Chemistry Answers BASIC CONCEPTS IN PHYSICAL AND INORGANIC CHEMISTRY 1.1 Formulae, Equations and Amounts of Substance 1 | Name | Formula | | --- | --- | | potassium carbonate | K2CO3 [1] | | silver(I) nitrate | AgNO3 [1] | | ammonium chloride | NH4Cl [1] | | sodium thiosulfate | Na2S2O3 [1] | | copper(II) chloride–2–water | CuCl2.2H2O [1] | | ammonium nitrate | NH4 NO3 [1] | | sodium hypochlorite | NaClO [1] | | aluminium sulfate | Al2 (SO4)3 [1] | | lithium nitrite | LiNO2 [1] | | zinc hydroxide | Zn(OH)2 [1] | | sodium hydrogensulfate | NaHSO4 [1] | | sodium chlorate | NaClO3 [1] | | ammonium carbonate | (NH4)2CO3 | | potassium phosphate | K3 PO4 [1] | | chromium(III) nitrate | Cr(NO3)3 [1] | | sodium sulfite | Na2SO3 [1] | | potassium hydrogencarbonate | KHCO3 [1] | | sodium chromate | Na2CrO4 [1] | | ammonium sulfate | (NH4)2SO4 [1] | | potassium permanganate | KMnO4 [1] | [20] Equations 2 (a) K2CO3 + 2HNO3 􀃆 2KNO3 + CO2 + H2O [1] (b) ZnO + 2HCl 􀃆 ZnCl2 + H2O [1] (c) 2Ca + O2 􀃆 2CaO [1] The answer Ca + ½O2 􀃆 CaO is equally acceptable and expected if 1 mole of Ca or 1 mole of CaO is required in the question. You will be required to write equations of this type in enthalpy work in AS2 . (d) H2 + Cl2 􀃆 2HCl [1] (e) 4NH3 + 5O2 􀃆 4NO + 6H2O [2] (f) CH4 + 2H2O 􀃆 CO2 + 4H2 [2] 1 BASIC CONCEPTS IN PHYSICAL AND INORGANIC CHEMISTRY (g) 4K2Cr2O7 􀃆 4K2CrO4 + 2Cr2O3 + 3O2 [2] (h) 3Cl2 + 6NaOH 􀃆 NaClO3 + 5NaCl + 3H2O [2] (i) Br2 + 2KI 􀃆 2KBr + I2 [1] (j) (NH4)2SO4 + 2NaOH 􀃆 Na2SO4 + 2NH3 + 2H2O [2] (k) BaCl2 + K2CrO4 􀃆 BaCrO4 + 2KCl [1] (l) Fe(NO3)3 + 3NaOH 􀃆 Fe(OH)3 + 3NaNO3 [2] (m) 2Pb(NO3)2 􀃆 2PbO + 4NO2 + O2 [2] (n) Ca + 2H2O 􀃆 Ca(OH)2 + H2 [1] (o) N2 + 3H2 􀃆 2NH3 [1] (p) 2SO2 + O2 􀃆 2SO3 [1] (q) 2NaOH + H2SO4 􀃆 Na2SO4 + 2H2O [1](r) 3 (a) OH– + H+ 􀃆 H2O [ 1] (b) Ag+ + I– 􀃆 AgI [ 1] (c) Cl2 + 2Br– 􀃆 2Cl– + Br2 [ 1] (d) CO 23– + 2H+ 􀃆 CO2 + H2O [ 1] (e) NH +4 + OH– 􀃆 NH3 + H2O [ 1] (f) O2– + 2H+ 􀃆 H2O [ 1] 4 (a) Cl2 (g) + 2NaI(aq) 􀃆 2NaCl(aq) + I2 (aq) [2] (b) NH3 (g) + HCl(g) 􀃆 NH4Cl(s) [2] (c) NH4 NO3 (s) + KOH(aq) 􀃆 NH3 (g) + KNO3 (aq) + H2O(l) [2] (d) 2AgNO3 (aq) + MgCl2 (aq) 􀃆

FAQs

What does this document provide for CCEA AS Chemistry students?

It provides a mark scheme with model answers and mark allocations aligned to the CCEA AS Chemistry specification, for use alongside the accompanying textbook.

Which topics are covered under Unit AS 1?

It covers basic concepts in physical and inorganic chemistry, including formulae, equations and amounts of substance, as well as Avogadro’s constant, the mole, molar mass, and related particle-count calculations.

Are alternative chemical equations accepted for stoichiometry questions?

Yes. The scheme explicitly states that an alternative equation form is equally acceptable and expected in cases where the required amount is specified in moles for calcium or calcium oxide.

Sep 30, 2026

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