Test misconceptions

• Ionisation requires a gaseous sample, so state symbols are (g).
• The element in p3 with the highest second ionisation energy value is Na.
• CCl2 has 2 BP and 1 LP so has a trigonal planar shape with a bond angle of 117.5.
• Tetrahedral molecules are not polar even if the bonds are polar because the shape is symmetrical so the dipoles cancel.
• The minor product is formed in smaller quantities because e.g. it is formed from the primary carbocation which is less stable than the secondary carbocation. This means it has a smaller positive inductive effect. The secondary carbocation is bonded to 2 alkyl groups while the primary is only bonded to one alkyl group.
• In an elimination from an alcohol to an alkene, the reagent is concentrated H2SO4 and the condition is hot.
• To distinguish between NaCl (aq) and BaCl2 (aq), use H2SO4. No observable change with NaCl, white precipitate with BaCl2.
• To distinguish between NaCl (aq) and Na2CO3 (aq) add acidified AgNO3. White precipitate with NaCl, no observable change with Na2CO3.
• To figure out the limiting reagent, find the moles of all reagents and compare to the equation ratio.
• Washing the inside of the conical flask with distilled water does not give an incorrect result as it doesn't affect moles.
• Rinsing the burette before filling it would dilute the acid, therefore a greater volume in titre would be required.
• Chromium is more stable with a half-filled sub-shell, so its electron configuration is 1s2 2s2 2p6 3s2 3p6 3d5 4s1.