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AQA A-Level Chemistry Question Cards Questions and Answers What is meant by activation energy? The minimum energy that a particle must have in order for a reaction to occur; the energy (enthalpy) difference between the reactants and the transition state. What is an aldehyde? An organic compound with the general formula RCHO. What is an alkane and what isthe general formula for the alkanes? A hydrocarbon with C-C and C-H single bonds only. General Formula = CnH2n+2 W...

AQA A-Level Chemistry Past Paper Questions and Answers 1) Shake the final solution in the flask. 2)Ensure the bottom of the (liquid)meniscus is on the graduation mark. 3)Wash the wet rod into the flask. Read the following instructions that describe how to make up a standard solution of a solid in a volumetric flask. Answer the questions which follow. "Take a clean 250cm3 volumetric flask. Use the balance provided and a clean, dry container, to weigh out the amount of solid required. Ti...

AQA A-level chemistry chemical tests Questions and Answers test for Carbon Dioxide (CO2 ) turns limewater milky (sparingly soluble Ca(OH) 2 forms insoluble CaCO3 ) Chlorine (Cl2 ) test bleaches damp litmus paper (Cl2 reacts with water to form HCl and HOCl) Hydrogen (H2 ) test pops with a lighted splint Oxygen (O2 ) test relights a glowing splint Carbonate (CO 3 2- ) test add dilute acid; effervescence, carbon dioxide produced Sulfate (SO4 2- ) test add d...

OCR A Level CHEMISTRY PAPER 1 Questions and Answers Test for carbonates - add dilute HCL - it makes carbon dioxide test for carbon dioxide by bubbling it through lime water Test for ammonium ions -add sodium hydroxide -warm the mixture -hover damp red litmus paper over it , if it turns blue the ions are present Test for sulphate ionz (SO4 2-) - add dilute HCL - then add BaCl2 - BaSO4 is made which is insoluble in water so a white precipitate will be formed Test for...

AQA A-level Chemistry Thermodynamics definitions Questions and Answers Enthalpy of Formation The enthalpy change when one mole of a compound is formed from its constituent elements under standard conditions, all reactants and products are in their standard states. Enthalpy of Combustion The enthalpy change when one mole of substance is burned completely in oxygen under standard conditions, all reactants and products in their standard states. Enthalpy of Atomisation The enthalpy...

AQA A Level Chemistry - Paper 3 Experiments Questions and Answers Make Up a Volumetric Solution 1. Weigh dry weighing boat 2. Place mass of solid into the boat and weigh accurately 3. Pour solid into a beaker. Reweigh empty weighing boat and calculate how much was transferred 4. Add deionised water and stir with glass rod until dissolved 5. Funnel into a volumetric flask 6. Make up to mark with deionised water until bottom of meniscus is on the mark 7. Stopper and invert to mix Ac...

AQA A-Level Chemistry (new spec) 1.1 Atomic Structure Questions and Answers Number of neutrons is worked out by... Subtracting the atomic number from the mass number Define isotopes Atoms of the same element with the same number of protons but a different amount of neutrons Isotopes have similar chemical properties because... they have the same electron configuration Isotopes have varying physical properties because... they have different masses Define ions A ch...

AQA A-Level Chemistry Aromatic Chemistry Questions and Answer State the three problems with Kekule's structure 1. C=C bonds are actually all the same length rather than the predicted 3 long single bonds and 3 short double bonds. 2. Benzene doesn't undergo addition reactions which you would expect trienes to readily undergo 3. Enthalpy change of hydrogenation is 152 kJ mol-1 less than expected. What are arenes? Hydrocarbons based on benzene Why do arenes have high melting...

AQA A Level Chemistry – Equilibria Questions and Answers What are the two characteristics of a system is in dynamic equilibrium? 1. both forward and backward reactions proceed at equal rate 2. the concentrations of the reactants and products remain constant What is Le Chatlier's principle used for? It is a tool to help predict the effects of temp, pressure and concentration on the position of equilibrium What happens to the position of equilibrium if temperature is increas...

Topic 1. Edexcel Chemistry A level Questions and Answers 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 neutrons in the nucleus of an atom of an element. What is an isotope? - Atoms of an element with the same number of protons but a different number of neutrons. - Same proton number but different mass number. ...

A-Level Chemistry Bond Angles and Shape Questions and Answers 2 electron pairs around the central atom Shape: Linear Bond Angle: 180 Example: Carbon Dioxide (CO2) 3 electron pairs around the central atom Shape: Trigonal planar Bond Angle: 120 Example: Boron Trifluoride (BF3) 4 electron pairs around the central atom Shape: Tetrahedral Bond Angle: 109.5 Example: Methane (CH4) 5 electron pairs around the central atom Shape: Trigonal bipyramid Bond Angle: 120 and 90 ...

Edexcel A-Level Chemistry Transition Metal Colours Questions and Answers What colours are MnO4- [+7] , MnO42- [+6], and Mn2+ [+2], in an aqueous complex? Purple, Green and Pale Pink respectively What colours are Ti3+ , Ti2+ in an aqueous complex Purple and Violet respectively What colours are VO2+ , VO2+ , V3+ and V2+ in an aqueous complex Yellow, Blue, Green, and Violet respectively What colours are CrO72- and Cr3+ in an aqueous complex Orange and green respectively ...

Common Questions A level chemistry unit 1 Questions and Answer Define the term relative atomic mass of an element. (2) mean mass of an atom of an element divided by one twelfth the mass of a carbon-12 atom State how the molecular mass of a covalent compound is obtained from its mass spectrum (1) the highest m/z value Explain why isotopes have identical chemical properties (1) they have the same electron configuration State what is meant by the term isotopes (1) atoms of...

A Level Chemistry Periodicity Questions and Answers Define group A vertical column. Elements in a group have similar chemical properties as they have the same number of outer shell electrons Define periodicity A repeating pattern of properties shown across different periods What is the s-block? Groups 1 and 2 What is the p-block? Groups 3-8 What is the d-block? Transition elements What is the f block? Lanthanides and actinides Define first ionisat...

AQA A-LEVEL CHEMISTRY Periodicity Questions and Answers BLOCKS What is the s, p, d and f block on the periodic table? S - 1,2 P - 3,4,5,6,7,8 D - Transition Metals F - Bottom. According to whatever the highest energy level is. ATOMIC RADIUS Why does the atomic radius decrease across the period? The increased number of protons pulls the electrons closer to it with minimal change in shielding to prevent that from ocurring. FIRST IONISATION ENERGY What is the genera...

Edexcel A level chemistry practicals Questions and Answers 8)b. measure enthalpy change of decomposition of KHCO3- key points and errors This practical combines two neutralisation reactions: 1. K2CO3 + 2HCL --> 2KCL + H2O +CO2 2. 2KHCO3 + 2HCL --> 2KCL +2H20 +2CO2 The desired reaction is: 2KHCO3 --> 2K2CO3 +CO2+ H2O use Q=mcΔT and ΔH=-Q/n Errors- assume specific heat capacity is the same as water. Heat lost to surroundings. Polystyrene is more insulating than glass so ...

A Level Chemistry - Structure and bonding Questions and Answers ionic bonding the strong electrostatic attraction between oppositely charged ions which two factors affect the strength of an ionic bond? ionic charge ionic radius (greater distance between ions = weaker bond) describe the trend in ionic radius down a group radius increases as atomic radius increases describe the trend in ionic radius for isoelectronic ions ionic radius decreases as atomic number increas...

AQA A-Level Chemistry - Aromatic Chemistry Questions and Answers Benzene An unsaturated carbon ring, with delocalised electrons in the centre, which cannot undergo addition reactions 152 Benzene is more stable than cyclohexene by a certain enthalpy change Electrophilic Substitution The mechanism to add a different R group to a benzene ring. This is the main type of reaction that occurs as the benzene ring is an area of high electron density so requires like charge displacement....

AQA A level Chemistry - test tube reactions Questions and Answers Bromide Ions and Chlorine Yellow/Orange solution Cl2 + 2Br- = Br2 + 2Cl Iodide ions and chlorine Yellow/brown solution Cl2 + 2I- = I2 + 2Cl- Chloride Ions and Bromine Yellow/orange solution No reaction Chloride Ions and Iodine Yellow/Brown solution No reaction Bromide Ions and Iodine Yellow/Brown solution No reaction Iodide ions and Bromine yellow/brown solution Br2 + 2I- = I2 +Cl- ...

Unit 1 - Higher Chemistry, Oxidizing and Reducing Agents Questions and Answers oxidation loss of electrons reduction gain of electrons Good reducing agents are? metals elements are good reducing agents as they have a low electronegativity which means they will lose their outer electrons easily Good oxidising agents are? non-metal elements are good oxidising agents as they have a high electronegativity which means they will gain electrons more easily What is a r...