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Excel A level chemistry paper 1 topics Questions and Answers Atoms Made up of 3 subatomic particles - electrons, neutrons and protons Electrons - Subatomic particle - Charge of -1 - Arranged in orbitals - Relative mass of 0.0005 - negligible Nucleus - Where most of the mass of the atom is contained - Made up of protons and neutrons - Diameter is much smaller than that of whole atom Neutrons - Subatomic particle - No charge - Relative mass of 1 - Contained in nuc...

A-Level Chemistry Ion Charges Questions and Answers hyrdogren H+ sodium Na+ silver Ag+ potassium K+ lithium Li+ ammonium NH4+ barium Ba+2 calcium Ca+2 copper(II) Cu+2 magnesium Mg+2 zinc Zn+2 lead Pb+2 iron(II) Fe+2 iron(III) Fe+3 aluminium Al+3 chloride Cl- bromide Br- fluoride F- iodide I- hydroxide OH- nitrate NO3- oxide O-2 ...

AQA A-Level Chemistry - Group 2 Questions and Answers Explain the trend in atomic radius down group 2 Increases down group. Explain the trend in 1st ionisation energy down group 2 -Decreases down group. -More shielding, weaker attraction as nucleus and outer e- further apart. - Easier to remove outer e- (less energy). Explain the trend in melting points down group 2 -Generally decrease down group (not Mg). -Larger ions, distance between + metal nuclei and delocalised e- is g...

OCR A-level Chemistry Reaction Conditions and Reagents Questions and Answers Haloalkane > Nitrile NaCN or KCN (CN-) and ethanol Alkane > Haloalkane Halogen and UV light Haloalkane > Amide NH3 and ethanol Nitrile > Amine H2 and Ni catalyst Haloalkane > Alcohol NaOH Alcohol > Haloalkane Sodium halide and H2SO4 Alkene > Alcohol H2O as steam and H3PO4 Alcohol > Alkene Conc. H2SO4 or H3PO4 and heat Secondary Alco...

AQA A-Level Chemistry Amount of Substance Questions and Answers What is the relative atomic mass? the ratio of the average mass of one atom of an element to one twelfth of the mass of an atom of carbon-12 (Oxford Languages). How do you work out the relative atomic mass? Why is carbon-12 so significant? Carbon-12's atomic mass could be measured particularly accurately compared to the other elements on the periodic table. Historically, chemists and physicists used oxygen to ...

OCR A-level Chemistry - Paper 3 Questions and Answers Why does HF have a higher boiling point than CH4? -Boiling point increases as electronegativity increases -HF has hydrogen bonding, CH4 has London forces How do you prepare a standard solution? -Weigh out correct mass of solid -Dissolve in distilled water -Transfer to a 250cm^3 volumetric flask -Wash beaker with distilled water -Add washings to the volumetric flask -Make up to 250cm^3 with distilled water -Invert to ensure mi...

Transition metals OCR A Level Chemistry Questions and Answers Which 2 transition metals do not have a fully filled 4s orbital? Chromium and copper What advantage does a fully or half filled shell give a transition metal and why? Makes more stable What is the definition of a transition element? D-block element which form at least one ion with a partially filled d orbital Which 2 elements in the d block do not qualify as transition metals and why? Zinc and scandium. Their...

Common exam questions A level chemistry unit 3 Questions and Answers What is meant by an unsaturated hydrocarbon? one which contains one or more carbon-carbon double bonds What is meant by the term hydrocarbon? a molecule that contains the elements hydrogen and carbon only Recall the reagents and conditions needed to produce ethanol from bromoethane. aqueous NaOH reflux Name the organic product and mechanism when 2-bromopropane reacts with ethanolic KOH. prop-1-ene el...

Tests for Ions- A-Level Chemistry Questions and Answers What is used to test for carbonates? Hydrochloric acid How do you know if the test result is positive for carbonates? Bubbles of CO2 released- tested with limewater How do you test for sulphates? Add dilute HCl and barium chloride solution How do you know if the test result is positive for sulphates? White precipitate formed of barium sulphate How do you test for halides? Add nitric acid and then silver nit...

A-level AQA Chemistry Transition Metals Questions and Answers Transition Metal Metal that can form one or more stable ions with a partially filled d sub-level. Scandium isn't a TM because... Has an empty d-shell when Sc3+ Zinc isn't a TM because... Has a full d-shell when Zn2+ Which 2 TM have 1 electron in 4s sub-level to give stability? Chromium and Copper Which sub levels electrons fill up first and empty first? 4s What physical properties do they...