Live practice

Apply ozone cleavage to the two Kekulé arrangements of o-xylene. Each arrangement gives a different set of dialdehyde/dicarbonyl fragments.

The inductive effect is permanent sigma-bond polarisation; the electromeric effect is temporary complete transfer of pi electrons during attack. Compare substituent electron withdrawal/donation.

Compare which oxidant is reduced by each substrate. Both Ag⁺ and Cu²⁺ oxidise H₃PO₂, but only Ag⁺ oxidises benzaldehyde under the stated test conditions.

Let x atm C₂H₆ dissociate. Then Kp=x²/(4−x)=0.04; the physical root is x≈0.38 atm.

Set ΔG=ΔH−TΔS equal to zero at the boundary. With both ΔH and ΔS positive, spontaneity occurs above this temperature.

Electronegativity is a relative, dimensionless tendency of a bonded atom to attract shared electrons. Electron-gain enthalpy is the measurable enthalpy change when an isolated gaseous atom gains an electron.

Na first loses its single 3s electron easily. Na⁺ then has a noble-gas shell, so its second electron would be removed from the core. Mg⁺ still has one 3s electron for its second ionisation.

The longest Balmer wavelength is the smallest Balmer energy gap, n=3 to n=2.

Use a 10⁶ g sample of solution. It contains \(15\,\mathrm{g}\) chloroform and approximately \(999985\,\mathrm{g}\) water.

Principle and reasoning. Work from the governing physical relation and apply it to every stated part.

The film has two surfaces, each exerting force Sl along the slider.