Unit 1 Revision questions and answers

The idea of these questions is to highlight areas that you need to revise the most. Use them however you wish. I used the specification to make the questions so most of Unit 1 is covered here. The website doesn't like subscripts and superscripts unfortunately, I apologise for that. Answers on the next page!1. Define the term mass number of an atom. 2. State the number of each type of fundamental particle present in a fluoride ion, F-. 3. Describe how ions in a mass spectrometer reach the detector. 4. What two things does the detector measure when ions reach it? 5. Give the electron configuration, in terms of s, p and d subshells, of chromium. 6. Define the term ionisation energy. 7. Give three factors which affect ionisation energy. 8. Define the term relative atomic mass. 9. Define the term relative molecular mass. 10. State the ideal gas equation. 11. Define the term empirical formula. 12. Define the term molecular formula. 13. Give an equation for atom economy. 14. What is meant by a dative covalent (coordinate) bond? 15. Why do the melting and boiling points of metals increase across a period? 16. Why do the melting and boiling points of metals decrease down a group? 17. Define the term electronegativity. 18. What can be said about the polarity of a covalent bond between atoms with a large difference in electronegativity? 19. What is the strongest type of intermolecular force, and when does it occur? 20. When do you get permanent dipole-dipole forces? 21. What are van der Waals’ forces? 22. Describe the crystal structure of graphite. 23. Why does graphite conduct electricity? 24. What is the general trend in first ionisation energy across Period 3 (Na-Ar)? 25. Which two elements deviate from this trend and why? 26. Name the alkane with structural formula CH3CH(CH3)CH(CH3)CH3. 27. Give the name and displayed formula of a chain-branching isomerism of the alkane above. 28. By what process are alkanes separated from crude oil? 29. State the meaning of a saturated hydrocarbon. 30. What are the conditions and the main types of products of thermal cracking? 31. What are the conditions and the main types of products of catalytic cracking? 32. Give an equation for the removal of NO from exhaust engines. 33. Identify a reagent used to remove industrial sulphur dioxide emissions and explain why it is used. 34. Draw and name the shape of a molecule of ClF4-, showing any lone pairs which influence the shape. 35. What is the bond angle in water?

See how you did, and use this proactively to focus your revision on areas you struggled on. Ask if you're not sure about any of the answers or if I've made a mistake.Unit 1 Answers 1. Number of protons + number of neutrons 2. 9 protons, 10 electrons, 10 neutrons 3. Accelerated by a negative plate; deflected by a magnetic field (greater m/z ratio = lower deflection) 4. M/z ratio of ions; relative abundance/size of current generated 5. 1s22s22p63s23p63d54s1 – remember it deviates from the trend as a half-full d subshell is more stable than 3d44s2. Can also be written as 4s13d5 6. The energy required to remove one electron from each atom of a mole of gaseous atoms of an element (to produce a mole of ions with a +1 charge) 7. Atomic radius (distance of outer electrons from nucleus), nuclear charge and electron shielding 8. Average mass of one atom of an element x12 Mass of one atom of carbon-12 9. Average mass of one molecule of a species x12 Mass of one atom of carbon-12 10. pV=nRT (p=pressure in Pa; V=volume in m3; n=moles; R=8.31kJmol-1 (given in question); T=temperature in Kelvin 11. The simplest ratio of the number of atoms of each element in a compound 12. The number of atoms of each element in a molecule 13. Mass of useful products x100% Total mass of products (or reactants) 14. A shared pair of electrons where both electrons originate from/are donated by the same atom 15. More delocalised electrons/bigger nuclear charge/smaller atomic radius; stronger electrostatic attraction between electrons and nuclei/positive ions; stronger metallic bonding. 16. Outer electrons further from nucleus/more electron shielding; electrostatic attraction between electrons and nuclei is weaker, so weaker metallic bonding 17. The power of an atom to withdraw electron density from a covalent bond 18. Very polar 19. Hydrogen bonds; when hydrogen is bonded to F, O or N 20. When you have a polar bond between atoms with a large difference in electronegativity, i.e. between an atom with a partial positive charge and one with a partial negative charge 21. Temporary forces caused by an instantaneous dipole in one atom which induces a dipole in a second atom of another molecule, resulting in a slight electrostatic attraction. The weakest type of intermolecular force 22. Giant covalent; carbon atoms arranged in hexagonal layers 23. Carbon atoms have delocalised electrons which can carry charge 24. Increases 25. Aluminium (outer electron in p subshell – further from nucleus than s subshell so weaker electrostatic attraction of electron to nucleus); sulphur (paired electrons in 3p orbital repel) 26. 2,3-dimethylbutane 27. Name and displayed formula of: hexane; 2-methylpentane; 3-methylpentane; 2,2-dimethylbutane; ethylbutane (any one) 28. Fractional distillation 29. Molecule containing only the elements carbon and hydrogen (hydrocarbon); with only single covalent bonds (saturated) 30. 500-900 degrees C; 70atm; short-chain alkanes and alkenes 31. 450 degrees C; 10atm; zeolite catalyst; motor fuels and aromatic hydrocarbons 32. 2NO + 2CO => N2 + 2CO2 33. Calcium oxide – it is basic so it neutralises the gas 34. Square planar (all bond angles 90o); two lone pairs on the chlorine. 35. 104.5o

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