OCR Chemistry Paper 2 Questions with Correct Answers

Reactivity Series - ANSWERSList of metals in order of reactivity, used to predict displacement reactions Displacement Reaction - ANSWERSWhen a more reactive metal displaces a less reactive metal in a compound Alkali Metals - ANSWERSGroup 1 metals that react with water to form hydroxides and hydrogen gas Smelting - ANSWERSProcess of extracting metals from ores using carbon as a reducing agent Reduction - ANSWERSChemical reaction where a substance gains electrons or loses oxygen Flame Test - ANSWERSMethod to identify metals by observing the color of the flame when heated Precipitate - ANSWERSSolid formed when two solutions react and a insoluble product is produced Halide Ions - ANSWERSIons of halogens like chlorine, bromine, or iodine Spectroscope - ANSWERSInstrument used to analyze the wavelengths of light emitted by a substance Moles per Decimetre Cubed - ANSWERSUnit of concentration representing the number of moles of solute per liter of solution Titrations - ANSWERSProcess to determine the concentration of an acid or alkali using a known volume of the other Electrolysis - ANSWERSChemical process using electricity to drive a non-spontaneous redox reaction Percentage Yield - ANSWERSRatio of actual yield to theoretical yield, indicating efficiency of a reaction Atom Economy - ANSWERSMeasure of efficiency in a chemical reaction, showing the proportion of reactant atoms that become part of the desired product Room Temperature and Pressure (RTP) - ANSWERSStandard conditions of 20°C and 1 atmosphere pressure used for gas volume calculations Rate of Reaction - ANSWERSSpeed at which reactants are converted into products in a chemical reaction Mean Rate - ANSWERSAverage rate over a period, considering rate changes Turbidity - ANSWERSIncreased cloudiness in a solution indicating reaction progress Gas Syringe - ANSWERSDevice measuring volume of gas produced in a reaction Activation Energy - ANSWERSEnergy needed to start a reaction, affected by temperature Catalyst - ANSWERSSubstance speeding up reaction without being consumed Reversible Reaction - ANSWERSReaction where products can revert to original reactants Equilibrium - ANSWERSState where forward and reverse reactions balance Le Chatelier's Principle - ANSWERSSystem adjusts to counteract changes to maintain equilibrium Ammonia - ANSWERSCompound used in fertilizers, made from hydrogen and nitrogen NPK Fertilizers - ANSWERSFertilizers containing nitrogen, phosphorus, and potassium Polymer - ANSWERSMaterial made of repeating units, can be thermosoftening or thermosetting Alloy - ANSWERSMixture of different metals, often stronger than pure metals Corrosion - ANSWERSGradual destruction of materials by chemical reactions Galvanizing - ANSWERSCoating metal with a more reactive metal to prevent corrosion