OCR A-LEVEL CHEMISTRY MODULE 2 Questions and Answers

OCR A-LEVEL CHEMISTRY MODULE 2 Questions and Answers ISOTOPES ATOMS OF THE SAME ELEMENT WITH DIFFERENT NUMBERS OF NEUTRONS ATOMIC (PROTON) NUMBER NUMBER OF PROTONS IN THE NUCLEUS MASS (NUCLEON) NUMBER NUMBER OF PARTICLES (PROTONS & NEUTRONS) IN THE NUCLEUS ION A POSITIVELY OR NEGATIVELY CHARGED ATOM OR (COVALENTLY BONDED) GROUP OF ATOMS RELATIVE ISOTOPIC MASS THE MASS OF AN ISOTOPE COMPARED WITH ON TWELTH OF THE MASS OF AN ATOM OFCARBON 12 RELATIVE ATOMIC MASS THE WEIGHTED MEAN MASS OF AN ATOM OF AN ELEMENT COMPARED WITH ONE TWELTH OF THE MASS OF AN ATOM OF CARBON 12. AMOUNT OF SUBSTANCE THE QUANTITY OF WHOSE UNIT IS THE MOLE. CHEMISTS USE 'AMOUNT OF SUBSTANCE' AS A MEANS OF COUNTING ATOMS AVOGADRO CONSTANT (NA OR L) THE NUMBER OF ATOMS PER MOLE OF THE CARBON 12 ISOTOPES (6.02x10^23 mol^-1) MOLE THE AMOUNT OF ANY SUBSTANCE CONTAINING AS MANY PARTICLES AS THERE ARE CARBON ATOMS IN EXACTLY 12g OF THE CARBON 12 ISOTOPE MOLAR MASS (Mr) THE MASS PER MOLE OF A SUBSTANCE. THE UNITS = g mol^-1 MOLECULE A SMALL GROUP OF ATOMS HELD TOGETHER BY COVALENT BONDS MOLAR VOLUME THE VOLUME PER MOLE OF A GAS. UNITS = dm^3 mol^-1. AT ROOM TEMPERATURE & PRESSURE, THE MOLAR VOLUME IS APPROXIMATELY 24.0 dm^3 mol^-1 CONCENTRATION OF A SOLUTION THE AMOUNT OF SOLUTE (IN MOL) DISSOLVED PER 1dm^3 OF SOLUTION STANDARD SOLUTION A SOLUTION OF KNOWN CONCENTRATION. STANDARD SOLUTIONS ARE NORMALLY USED IN TITRATIONS TO DETERMINE UNKNOWN INFORMATION ABOUT ANOTHER SUBSTANCE. SPECIES ANY TYPE OF PARTICLE THAT TAKES PLACE IN A CHEMICAL REACTION STOCHIOMETRY THE MOLAR RELATIONSHIP BETWEEN THE RELATIVE QUANTITIES OF SUBSTANCES TAKING PART IN A REACTION HYDRATED REFERS TO A CRYSTALLINE COMPOUND CONTAINING WATER MOLECULES ANHYDROUS REFERS TO A SUBSTANCE THAT CONTAINS NO WATER MOLECULES WATER OF CRYSTALLISATION REFERS TO WATER MOLECULE THAT FORM AN ESSENTIAL PART OF THE CRYSTALLINE STRUCTURE OF A COMPOUND R.A.M (%MASS 1 + %MASS 2 + %MASS 3) / 100% MOLES, n n = m/Mr GAS MOLES, n n = V(dm3)/ 24 OR V(cm3)/24000 CONC & VOL MOLES, n n = c x V (in dm3) IDEAL GAS EQUATION pV = nRT (R=8.31 J K^-1 mol^-1) % YIELD 100 X (actual amount in mol of product)/(theoretical amount in mol of product) % ATOM ECONOMY 100 X (molecular mass of the desired product)/(sum of molecular masses of all products) ACID PROTON DONOR BASE PROTON ACCPETOR ALKALI TYPE OF BASE THAT DISSOLVES IN WATER FORMING OH- IONS SALT ANY CHEMICAL COMPOUND FORMED FROM AN ACID WHEN A H+ ION FROM THE ACID HAS BEEN REPLACED BY A METAL ION OR ANOTHER POSITIVE ION (SUCH AS AMMONIUM NH4+) CATION POSITIVELY CHARGED ION ANION NEGATIVELY CHARGED ION OXIDATION NUMBER A MEASURE OF THE NUMBER OF ELECTRONS THAT AN ATOM USES TO BOND WITH ATOMS OF ANOTHER ELEMENT. OXIDATION NUMBERS ARE DERIVED FROM A SET OF RULES OXIDATION IS LOSS OF ELECTRONS. INCREASE IN OXIDATION NUMBER. REDUCTION GAIN OF ELECTRONS. DECREASE IN OXIDATION NUMBER. REDOX REACTION A REACTION IN WHICH BOTH REDUCTION AND OXIDATION TAKE PLACE. REDUCING AGENT REAGENT THAT REDUCES (DONATES ELECTRONS TO) ANOTHER SPECIES OXIDISING AGENT REAGENT THAT OXIDISES (ACCEPTS ELECTRONS FROM) ANOTHER SPECIES SHELL A GROUP OF ATOMIC ORBITALS WITH THE SAME PRINCIPLE QUANTUM NUMBER, n. ALSO KNOWN AS MAIN ENERGY LEVEL. PRINCIPAL QUANTUM NUMBER (n) A NUMBER REPRESENTING THE RELATIVE OVERALL ENERGY OF EACH ORBITAL, WHICH INCREASES WITH DISTANCE FROM THE NUCLEUS. THE SETS OF ORBITALS WITH THE SAME N-VALUE ARE REFERRED TO AS ELECTRON SHELLS OR ENERGY LEVELS. ATOMIC ORBITAL REGION WITHIN AN ATOM THAT CAN HOLD UP TO 2 ELECTRONS WITH OPPOSITE SPINS. SUB-SHELL GROUP OF THE SAME TYPE OF ATOMIC ORBITALS (S,P,D,F) WITHIN A SHELL. ELECTRON CONFIGURATION ARRANGEMENT OF ELECTRONS IN AN ATOM COMPOUND A SUBSTANCE FORMED FROM 2 OR MORE CHEMICALLY BONDED ELEMENTS IN A FIXED RATIO, USUALLY SHOWN BY A CHEMICAL FORMULA. IONIC BOND ELECTROSTATIC ATTRACTIN BETWEEN OPPOSITELY CHARGE IONS GIANT IONIC LATTICE A THREE-DIMESIONAL STRUCTURE OF OPPOSITELY CHARGED IONS, HELD TOGETHER BY STRONG IONIC BONDS GROUP VERTICAL COLUMN OF THE PERIODIC TABLE. ELEMENTS IN SAME GROUP HAVE SIMILAR CHEMICAL PROPERTIES AND THEIR ATOMS HAVE THE SAME NUMBER OF OUTER-SHELL ELECTRONS. COVALENT BOND STRONG ELECTROSTATIC ATTRACTION BETWEEN A SHARED PAIR OF ELECTRONS AND THE NUCLEI OF THE BONDED ATOMS LONE PAIR AN OUTER-SHELL PAIR OF ELECTRONS THAT IS NOT INVOLVED IN CHEMICAL BONDING DATIVE COVALENT OR COORDINATE BOND SHARED PAIR OF ELECTRONS WHICH HAS BEEN PROVIDED BY ONE OF THE BONDING ATOMS ONLY. ELECTRONEGATIVITY A MEASURE OF THE ATTRACTION OF A BONDED ATOM FOR THE PAIR OF ELECTRONS IN A COVALENT BOND PERMANENT DIPOLE A SMALL CHARGE DIFFERENCES ACROSS A BOND THAT RESULTS FROM A DIFFERENCE IN ELECTRONEGATIVITIES OF THE BONDED ATOMS INTERMOLECULAR FORCE AN ATTRACTIVE FORCE BETWEEN NEIGHBOURING MOLECULES PERMANENT DIPOLE-DIPOLE FORCE A WEAK ATTRACTIVE FORCE BETWEEN PERMANENT DIPOLES IN NEIGHBOURING POLAR MOLECULES LONDON DISPERSION FORCES ATTRACTIVE FORCES BETWEEN INDUCED DIPOLES IN NEIGHBOURING MOLECULES. HYDROGEN BOND A STRONG DIPOLE-DIPOLE ATTRACTION BETWEEN: AN ELECTRON DEFICIENT HYDROGEN ATOM ON ONE MOLECULE; AND A LONE PAIR OF ELECTRONS ON A HIGHLY ELECTRONEGATIVE ATOM (O, N OR F) ON A DIFFERENT MOLECULE SIMPLE MOLECULAR LATTICE A THREE-DIMENSIONAL STRUCTURE OF MOLECULES, BINDED TOGETHER BY WEAK INTERMOLECULAR FORCES TETRAHEDRAL 109.5 ° LINEAR 180° NON LINEAR 104.5°