During compression of a spring the work done is 10kJ and 2kJ escaped to the surroundings as heat. The change in internal energy, $$\Delta $$U(inkJ) is :

Hinsberg's reagent is :

Molal depression constant for a solvent is 4.0 kg mol^–1. The depression in the freezing point of the solvent for 0.03 mol kg^–1 solution of K₂SO₄ is :
(Assume complete dissociation of the electrolyte)

The peptide that gives positive ceric ammonium nitrate and carbylamine tests is :