NCEA Level 2 Organic Chemistry Questions and Answers 2023

NCEA Level 2 Organic Chemistry Questions and Answers 2023 Alkanes A homologous series of saturated hydrocarbons made of C-H and C-C single bonds Alkenes A homologous series of unsaturated hydrocarbons containing one C=C double bond Alkynes A homologous series of unsaturated hydrocarbons with one C to C triple bond Haloalkane An alkane that has had an H substituted for a halogen (eg Br or Cl) Amine An alkane where an H has been replaced with an NH₂group Alcohols A homologous series of hydrocarbons with an OH group attached Carboxylic acids A homologous series of hydrocarbons with an attached COOH group Which hydrocarbons are water soluble? Alcohols, Amines, Carboxylic acids Which hydrocarbons are colourless? All of them Which hydrocarbons conduct electricity? Carboxylic acids and Amines Which hydrocarbons are acidic (turn litmus red) in solution? Carboxylic Acids Which hydrocarbons are basic (turn litmus blue) in solution? Amines Primary The N is joined to only one other carbon (Amines) The carbon to which the functional group is attached has only one other carbon attached to it Secondary The N is joined to two other carbons (Amines) The carbon to which the functional group is attached has two other carbons attached to it Tertiary The N is joined to three other carbons (Amines) The carbon to which the functional group is attached has three other carbons attached to it Structural isomer substances with the same molecular formula but different structural formula Geometric isomer substances with the same molecular and structural formula, but a different arrangement of atoms in space due to an unrotatable double bond Addition of alkenes to form alkanes requires... H₂ with a platinum catalyst Addition of alkenes to form dihaloalkane requires... Br₂ no catalyst (rapid reaction) Addition of alkenes to form alcohols requires... H₂O with an acid catalyst Addition of alkenes to form haloalkane requires... A Hydrogen Halide (eg HBr, HCl) Addition polymerisation of alkenes requires... alkenes, high heat and pressure Substitution of alkanes to form haloalkanes require... halogen (eg Br₂) UV catalyst (slow reaction), hydrogen halide produced also Substitution reactions of alcohols to form haloalkanes require... SOCl₂ PCl₃ or PCl₅ Substitution of haloalkanes to form amines require... alcoholic ammonia (NH3/OH) Substitution of haloalkanes to form alcohols require... Aqueous KOH Oxidation of primary alcohols to form carboxylic acids require... Acidified potassium permanganate or acidified potassium dichromate (MnO₄⁻/H⁺, Cr₂O₇/H⁺) Oxidation of Alkenes to form a -diol require... MnO₄⁻