AQA A Level Chemistry Paper 2 Exam Questions With 100% Verified Solutions

AQA A Level Chemistry Paper 2 Exam Questions With 100% Verified Solutions What does cisplatin look like? - ANSWER How does cisplatin prevent DNA replication? - ANSWER Ligand substitution forms bond between Platinum and nitrogens from two guanines; inhibiting the unzipping of the DNA strands as the DNA structure is disrupted. Why can cisplatin cause more harm than good? - ANSWER as cisplatin is not selective, normal cells are also stopped from replicating, causing side effects like hair loss. What happens when cisplatin passes the membrane? - ANSWER Chlorine ligands are substituted by H2O ligands how can the side effects of cisplatin be lessened - ANSWER by giving patients very low dosages OR to just target the tumour by using a method that delivers the drug only to the cancer cells so it doesnt get the chance to attack healthy cells DNA sequence damaging/altering can be caused by: - ANSWER radiation carcinogenic chemicals What is the geometry of the anti-cancer drug, cis-platin? - ANSWER square planar closed system - ANSWER where reactants and products can neither be added nor removed. dynamic equilibrium - ANSWER the rate of the forward reaction equals the rate of the backward reaction. why is equilibrium dynamic? - ANSWER The equilibrium is dynamic because both the forward and backward reactions are still taking place. When is dynamic equilibrium reached? - ANSWER if a reversible reaction takes place in a closed system Le Chatelier's Principle - ANSWER when a change is imposed on an equilibrium, the equilibrium position will shift to oppose the change. What factors affect the position of equilibrium? - ANSWER temperature. pressure. concentration. Do catalysts affect equilibrium? - ANSWER Catalysts have NO effect on the position of equilibrium. A catalyst speeds up the rate of the forwards and backwards reactions EQUALLY. What's a disadvantage of high pressure reactions? - ANSWER it's very expensive to create and maintain high pressures. What are the conditions used in the synthesis of ethanol? - ANSWER 300 degrees celcius and 65 atmospheres What does a Kc greater than one indicate? - ANSWER that the forward reaction dominates. What is Kc? - ANSWER The equilibrium constant is a constant for a particular reaction at a particular temperature. Stoichiometric factor - ANSWER This is the coefficient that is in front of each species in the reaction equation. What type of reaction is the forward reaction in the haber process? - ANSWER the forward reaction is exothermic what does P and S form? - ANSWER S8 (s) and P4 (s) Pros of incineration - ANSWER reduces landfill space cons of incineration - ANSWER toxic gases and greenhouse gases are produced pros of recylcing - ANSWER Recycling saves raw materials, which is important when considering that many polymers are produced from crude oil. cons of recylcing - ANSWER Polymers need to be separated and organised. This is an expensive process. phosphoric acid - ANSWER what's the other way amino benzene can be made from nitrobenzene? - ANSWER Hydrogen gas with a nickel catalyst then NaOH what ligands are substituted when cisplatin enters the body? - ANSWER Cl Pt(NH3)2(H2O)2 prefix for ketones and aldehydes - ANSWER oxo benzene bpt compared to hexane - ANSWER similar bpt due to similar no. of e- benzene mpt copared to hexane - ANSWER benzene mpt is higher as planar so stack well together (stronger van der waal forces) combustion of arenes to more saturated compounds - ANSWER burn w/ much smokier flame due to low C:H ratio reactivity of arenes - ANSWER react w/ electrophiles (due to high e- density) react via SUBSTITUTION to maintain stability of the benzene ring HNO3 + H2SO4 - ANSWER +NO2 + HSO4- + H2O thermal cracking - ANSWER high temperature (1000C) and high pressure (70atm or 7000kPa) a high percentage of alkenes and comparatively few alkanes (sometimes produces hydrogen) explain the positive inductive effect - ANSWER Alkyl groups push electrons and so help to stabilise adjacent positive charge. How can we make polymers more flexible? - ANSWER By adding a plasticiser How do plasticisers make polymers more flexible? - ANSWER They stick between the chains and keep the polymers further apart from each other, weakening the van der Waals forces and lets chains slide more easily.