Topic 10 - Organic chemistry
Question 1
SLPaper 1Which compound can be oxidized when heated with an acidified solution of potassiumdichromate(VI)?
Question 2
SLPaper 3Stearic acid (_M_r = 284.47) and oleic acid (_M_r = 282.46) have the same number of carbon atoms. The structures of both lipids are shown in section 34 of the data booklet.
The iodine number is the number of grams of iodine which reacts with 100 g of fat. Calculate the iodine number of oleic acid.
State one impact on health of the increase in LDL cholesterol concentration in blood.
Explain why stearic acid has a higher melting point than oleic acid.
State one similarity and one difference in composition between phospholipids and triglycerides.
Similarity:
Difference:
d(i).
Identify a reagent that hydrolyses triglycerides.
d(ii).
Question 3
SLPaper 1What is the major product of the reaction between HCl and but-2-ene?
Question 4
SLPaper 1Which monomer would produce the polymer shown?
Question 5
HLPaper 2The photochemical chlorination of methane can occur at low temperature.
Question 6
HLPaper 3Changes in physiology can impact living creatures.
The graph shows the change in oxygen partial pressure in blood, measured at different pH values.
Explain the effect of changing pH on the percentage saturation of hemoglobin at a given partial pressure of oxygen.
Explain the biomagnification of the pesticide DDT.
Vitamins are organic compounds essential in small amounts.
State the name of one functional group common to all three vitamins shown in section 35of the data booklet.
Question 7
SLPaper 3Infrared (IR) spectroscopy is often used for the identification of polymers, such as PETE, forrecycling.
LDPE and high density polyethene (HDPE) have very similar IR spectra even thoughthey have rather different structures and physical properties.
Below are the IR spectra of two plastics (A and B); one is PETE, the other is lowdensity polyethene (LDPE).
Deduce, giving your reasons, the identity and resin identification code (RIC) of A and Busing sections 26 and 30 of the data booklet.
Describe the difference in their structures.
Explain why the difference in their structures affects their melting points.
Question 8
SLPaper 1Which is in the same homologous series as CH3OCH3?
Question 9
HLPaper 1Which compound has the lowest boiling point?
Question 10
HLPaper 2Compound A is in equilibrium with compound B.
Predict the electron domain and molecular geometries around the oxygen atom of molecule A using VSEPR
State the type of hybridization shown by the central carbon atom in molecule B.
State the number of sigma (σ) and pi (π) bonds around the central carbon atom in molecule B.
The IR spectrum of one of the compounds is shown:
COBLENTZ SOCIETY. Collection © 2018 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved.
Deduce, giving a reason, the compound producing this spectrum.
Compound A and B are isomers. Draw two other structural isomers with the formula C3H6O.
The equilibrium constant, Kc, for the conversion of A to B is 1.0×108 in water at 298 K.
Deduce, giving a reason, which compound, A or B, is present in greater concentration when equilibrium is reached.
f(i).
Calculate the standard Gibbs free energy change, ∆G⦵, in kJ mol–1, for the reaction (A to B) at 298 K. Use sections 1 and 2 of the data booklet.
f(ii).
Propanone can be synthesized in two steps from propene.Suggest the synthetic route including all the necessary reactants and steps.
g(i).
Propanone can be synthesized in two steps from propene.
Suggest why propanal is a minor product obtained from the synthetic route in (g)(i).
g(ii).
