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A-Level Chemistry Paper 1 Definitions Questions and Answers Orbital A region around the nucleus that can hold up to two electrons with opposite spins First Ionisation Energy The energy required to remove 1 mole of electrons from 1 mole of gaseous atoms Ionic bonding The electrostatic attraction between positive and negative ions Covalent bonding The strong electrostatic force of attraction between a shared pair of electrons and the nuclei of the bonded atoms Dati...

AQA A Level Chemistry Required Practical 10 Questions and Answers Why is the minimum volume of solvent used ? To make a saturated solution To increase the yield of the compound (enable crystallisation on cooling) Why do you hot filter the solution ? Remove insoluble impurities Prevent crystals reforming Why do you need to cool the beaker solution in ice ? Crystals reform (ice increases yield) Soluble impurities in solution Why use suction filtration ? The water pum...

OCR Chemistry A-Level - Modules 1-4 Questions and Answers what is water of crystallisation? water molecules that make up part of the crystal structure of a solid define relative isotopic mass the ass of an atom of an isotope of an element relative to one twelfth the mass of an atom of C-12 why is relative atomic mass written as a decimal? it is a weighted average mass define molecular formula the actual number of atoms of each element in a compound define what...

AQA A Level Chemistry - Shapes of Molecules Questions and Answers V-Shaped 118 2 bonding pairs, 1 lone pair, 118 Tetrahedral 4 bonding pairs, 0 lone pairs, 109.5 Pyramidal 3 bonding pairs, 1 lone pair, 107 V-Shaped 104.5 2 bonding pairs, 2 lone pairs, 104.5 Trigonal Bipyramid 5 bonding pairs, 0 lone pairs, 120 + 90

3.1.4 Energetics, A Level Chemistry, AQA Questions and Answers What values of deltaH do exothermic reactions have? Negative (less than 0) What values of deltaH do endothermic reactions have? Positive (more than 0) What do exothermic reactions do with energy? Give out energy What do endothermic reactions do with energy? Absorb energy Are oxidation reactions endo or exothermic? Exothermic Is combustion endo or exothermic? Exothermic Are thermal deco...

A-level AQA chemistry mechanisms Questions and Answers constant product for every nucleophilic addition-elimination of an acyl chloride HCl nucleophilic addition mechanism for carbonyls in nucelophilic addition mechanisms with carbonyls and cyanide ions, where do the cyanide ions come from KCN or NaCN (but not HCN bc it's highly toxic) in nucelophilic addition mechanisms with carbonyls and :H-, where does the :H- come from reducing agent what is the reducing ag...

AQA A Level Chemistry Aldehydes and Ketones Questions and Answers What is a carbonyl group? C=O What type of bond is C=O? Polar What are the effects of the carbonyl group being planar? There is no steric hindrance, so the bond can be attacked from any angle Why do nucleophiles attack carbonyl groups? The carbon is slightly positive How do you turn a primary alcohol into an aldehyde? Oxidise it How to you turn a carboxylic acid into an aldehyde? Reduce it...

AQA A-Level Chemistry (new spec) 1.3 Bonding Questions and Answers Ionic Bonding The electrostatic force of attraction between two oppositely charged ions formed by electron transfer Covalent Bonding A shared pair of electrons Dative Covalent Bonding (AKA Co-ordinate bonding) Formed when the shared pair of electrons in the covalent bond come from only one of the bonding atoms. Metallic Bonding The electrostatic force of attraction between the positive metal cations an...

AQA A-LEVEL CHEMISTRY PERIOD 3 Questions and Answers reaction of sodium with water- observation Floats, fizzes and moves on the surface of the water, molten. melts into a ball and disappears pH of sodium with water alkali, 12-14 sodium oxide formula Na2O What is the structure bonding in NaO ionic lattice, ionic bonding between Na+ ions an O2- ions Why is the melting point of sodium oxide high? ionic lattice with strong electrostatic forces of attraction between ...

AQA A Level Chemistry 3.1.12 - Acids and Bases Questions and Answers Bronsted-Lowry acid Proton donor Bronsted-Lowry base Proton acceptor pH Measure of acidity by measuring concentration of H⁺ ions. Low pH means Acidity High pH means Alkalinity Calculating pH pH = -log [H⁺] Calculating [H⁺] -pH [H⁺] = 10 What does an acid/base reaction involve? Transfer of the H⁺ from the acid to the base. Strong acid Fully dissociate...

AQA A level Chemistry 3.1.8 – Thermodynamics Questions and answers correct What are standard conditions? 298K/25°C 100kPa/1 atm 1 moldm-3 Enthalpy change of formation The enthalpy change when 1 mole of a compound is formed from its constituent elements under standard conditions, with all reactants and products in their standard states. Enthalpy change of combustion The enthalpy change when 1 mole of a substance is burned completely in oxygen. Enthalpy change of atom...

Aqa A level Chemistry Energetics Definitions and Formulas Questions and Answers Standard Enthalpy Of Formation The enthalpy change that takes place when one mole of a compound is formed from its constituent elements under standard conditions; all products and reactants in their standard states Standard Enthalpy Of Combustion The enthalpy change that takes place when one mole of a compound completely reacts with oxygen under standard conditions with all reactants and products being in ...

Aqueous ions a level chemistry aqa Questions and Answers Aqueous ion formula for Iron (11) and what colour is it [Fe(H2O)6]2+ (aq) green solution Aqueous ion formula for copper (11) what colour is it [Cu(H2O)6]2+ blue solution Aqueous ion Iron (111) and what colour is it [Fe(H2O)6]3+ (aq) purple solution may look yellow-brown due to [Fe(H2O)5(OH)]2+ Aqueous ion Aluminium (111) and what colour is it [Al(H2O)6]3+(aq) colourless solution Iron (11) aqueous ion plus N...

AQA A-level Chemistry Topic 1.4 - TOF Mass Spectrometry Questions and Answers What are the two types of ionisation for a mass spectrometer? Electron impact Electrospray ionisation Describe the stages of electron impact. 1. High energy electrons are fired at the sample using an electron gun. 2. This knocks off an electron from each atom/molecule to form 1+ ions. Describe the stages of electrospray ionisation. 1. The sample is dissolved in a volatile solvent (e.g. methanol or w...

OCR A-Level Chemistry Chapter 7 – Periodicity Questions and Answers Atomic Number Factor by which elements are arranged from left to right along periodic table Group Vertical column containing elements with the same number of outer shell electrons and similar properties Period Horizontal row by which it's number is the number of the highest energy shell of elements within that row Mendeleev Father of the modern periodic table Periodicity Repeating trends in...

A Level Chemistry common ion Questions and Answers hydrogen H⁺ lithium Li⁺ sodium Na⁺ potassium K⁺ magnesium Mg²⁺ calcium Ca²⁺ barium Ba²⁺ aluminium Al³⁺ fluoride F⁻ chloride Cl⁻ bromide Br⁻ iodide I⁻ oxide O²⁻ sulfide S²⁻ silver Ag⁺ zinc Zn²⁺ copper (I) Cu⁺ copper (II) Cu²⁺ chromium (II) Cr²⁺ chr...

AQA A Level Chemistry Year 2 - Rate Equations Questions and Answers From what time is the initial rate of reaction measured? t=0 What is a rate equation? An expression showing how the rate of reactions is linked to the concentration of the reactants What is the rate equation for the reaction : A + B --> C Rate = k[A]^m[B]^n The product concentrations are included in the rate equation True or False False What is the order of reaction with respect to a particu...

AQA A-level Chemistry Paper 1 Questions and Answers Explain what is meant by the term co-ordinate bond a covalent bond in which both electrons are donated by one atom Define the term Ligand Atom, ion or molecule which can donate a pair of electrons to a metal ion What can lattice enthalpy defined as? (2 things) Lattice enthalpy of formation and lattice enthalpy of dissociation Why is the experimental value for lattice dissociation of some compounds greater than the theor...

AQA A-Level Chemistry - Carboxylic Acids and Derivatives Questions and Answers Carboxyl group -COOH Naming Carboxylic Acids - Suffix (-oic acid) always at end of name, and chain - Numbering of carbons always starts at COOH end - Suffix (-dioic acid) implies carboxylic acid groups on both ends Acidity of Carboxylic Acids - Weak acids in water - slightly dissociate - Strong enough to displace CO2 from carbonates - E.g. CH3CO2H(aq) ⇌ CH3CO2-(aq)+ H+(aq) Solubility of...

Topic1. Excel Chemistry A level Questions and answers What is the relative mass of protons, neutrons and electrons? Protons: 1 Neutrons: 1 Electrons: 1/1840 What is the relative charge of protons, neutrons and electrons? Protons: +1 Neutrons: 0 Electrons: -1 What is atomic number? -The number of protons in the nucleus of an atom of an element. -All atoms of the same element have the same number of protons. What is the mass number? The total number of protons and ne...